diff --git a/axlearn/common/trainer_config_modifier.py b/axlearn/common/trainer_config_modifier.py
index d647e1a06..63d0e5c4b 100644
--- a/axlearn/common/trainer_config_modifier.py
+++ b/axlearn/common/trainer_config_modifier.py
@@ -2,12 +2,13 @@
 
 """Defines trainer config modifiers, which will be used in model definitions."""
 
-from typing import Dict, Sequence, Union
+from typing import Callable, Dict, NamedTuple, Sequence, Union
 
 from axlearn.common import config
 from axlearn.common.base_layer import RematSpec
 from axlearn.common.config import (
     REQUIRED,
+    ConfigBase,
     ConfigModifier,
     ConfigOr,
     Required,
@@ -17,7 +18,53 @@
 from axlearn.common.gradient_accumulation import with_minibatch_steps
 from axlearn.common.metrics import MetricAccumulator
 from axlearn.common.trainer import SpmdTrainer
-from axlearn.common.utils import HybridMeshShape, MeshShape
+from axlearn.common.utils import HybridMeshShape, MeshShape, PartitionSpec
+
+
+class _FoundModule(NamedTuple):
+    """Module found in recursive search of matching module."""
+
+    # The module found
+    module: ConfigModifier.Config
+    # The parent of the module found
+    parent_module: ConfigModifier.Config
+    # Key of the found module in parent
+    key_in_parent: ConfigModifier.Config
+
+
+def _find_target_module(module_name: str, cfg: SpmdTrainer.Config) -> _FoundModule:
+    """Recursively search for the target module matching module_name in provided cfg.
+
+    Args:
+        module_name: Name of the target module
+        cfg: The trainer config to be searched for module_name
+
+    Raises:
+        ValueError: The module_name is not found.
+
+    Returns:
+        A Tuple(curr_module, key_in_parent, parent_module)
+            curr_module: Module found
+            parent_module: The parent module
+            key_in_parent: Key in parent for the found module
+    """
+
+    # Here we assume x.y.z format.
+    # One example would be model.decoder.transformer.layer.
+    target_modules = module_name.split(".")
+    curr_module = cfg
+    key_in_parent = None
+    parent_module = None
+
+    for target_module in target_modules:
+        if not hasattr(curr_module, target_module):
+            raise ValueError(f"{target_module} is not found in {curr_module}.")
+        parent_module = curr_module
+        key_in_parent = target_module
+        curr_module = getattr(curr_module, target_module)
+    return _FoundModule(
+        module=curr_module, parent_module=parent_module, key_in_parent=key_in_parent
+    )
 
 
 class GradientAccumulationModifier(ConfigModifier):
@@ -100,18 +147,11 @@ def __call__(self, cfg: SpmdTrainer.Config) -> SpmdTrainer.Config:
         """
 
         for module_name, remat_spec in self._remat_policies.items():
-            # Here we assume x.y.z format.
-            # One example would be model.decoder.transformer.layer.
-            target_modules = module_name.split(".")
-            curr_module = cfg
-            for target_module in target_modules:
-                if not hasattr(curr_module, target_module):
-                    raise ValueError(f"{target_module} is not found in {curr_module}.")
-                curr_module = getattr(curr_module, target_module)
+            found_module = _find_target_module(module_name, cfg)
             # Here we assume all modules have remat_spec attribute.
-            if not hasattr(curr_module, "remat_spec"):
-                raise ValueError(f"{curr_module} does not have remat_spec attribute")
-            curr_module.remat_spec = remat_spec
+            if not hasattr(found_module.module, "remat_spec"):
+                raise ValueError(f"{found_module.module} does not have remat_spec attribute")
+            found_module.module.remat_spec = remat_spec
         return cfg
 
 
@@ -146,6 +186,113 @@ def __call__(self, cfg: SpmdTrainer.Config) -> SpmdTrainer.Config:
         return cfg
 
 
+class ModelConfigModifier(ConfigModifier):
+    """Update the model config for the trainer config."""
+
+    @config_class
+    class Config(ConfigModifier.Config):
+        """Configure ModelConfigModifier.
+
+        Attributes:
+            model_cfg_modifications: A mapping from module path
+                (e.g. `model.decoder.transformer.layer`) to a Config.
+        """
+
+        model_cfg_modifications: Dict[str, Callable[[ConfigBase], ConfigBase]] = {}
+
+    def __init__(self, cfg: Config):
+        super().__init__(cfg)
+        self._model_cfg_modifications = self.config.model_cfg_modifications
+
+    def _merge_configs(self, target_cfg: ConfigBase, found_module: ConfigBase) -> ConfigBase:
+        """Merge configurations from the config being replaced on a best effort basis.
+
+        Args:
+            target_cfg: configuration that will replace found_module.
+            found_module: existing configuration whose class will be replaced
+                but it's confguration will be merged with target_cfg.
+
+        Returns:
+            The modified config.
+
+        """
+        for key in target_cfg.keys():
+            if key == "klass":
+                continue
+            elif hasattr(found_module.module, key) and hasattr(target_cfg, key):
+                setattr(target_cfg, key, getattr(found_module.module, key))
+        return target_cfg
+
+    def __call__(self, cfg: SpmdTrainer.Config) -> SpmdTrainer.Config:
+        """Overwrite the model config of the specified modules.
+
+        Args:
+            cfg: The trainer config to be modified.
+
+        Raises:
+            ValueError: The target module is not found.
+
+        Returns:
+            The modified trainer config.
+        """
+
+        # Iterate over modules in the mapping, modules are sorted based on module name length.
+        # This ensures parent is modified before children to avoid missing modifications.
+        for module_name, model_cfg in sorted(
+            self._model_cfg_modifications.items(), key=lambda item: len(item[0])
+        ):
+            found_module = _find_target_module(module_name, cfg)
+
+            model_cfg = self._merge_configs(model_cfg, found_module)
+            # Replace in the parent config
+            setattr(found_module.parent_module, found_module.key_in_parent, model_cfg)
+        return cfg
+
+
+class PartitionSpecModifier(ConfigModifier):
+    """Update the partition spec attribute for the specified modules."""
+
+    @config_class
+    class Config(ConfigModifier.Config):
+        """Configure PartitionSpecModifier.
+
+        Attributes:
+            partition_specs: A nested mapping from module path
+                (e.g. `model.decoder.transformer.layer`) to another
+                mapping of model attribute to PartitionSpec.
+        """
+
+        partition_specs: Required[Dict[str, PartitionSpec]] = REQUIRED
+
+    def __init__(self, cfg: Config):
+        super().__init__(cfg)
+        self._attribute_dicts = self.config.partition_specs
+
+    def __call__(self, cfg: SpmdTrainer.Config) -> SpmdTrainer.Config:
+        """Update the partition_spec attributes for the specified modules.
+
+        Args:
+            cfg: The trainer config to be modified.
+
+        Raises:
+            ValueError: The target module is not found.
+            ValueError: The partition_spec attribute is not found.
+
+        Returns:
+            The modified trainer config.
+        """
+        for module_name, partition_spec_dict in self._attribute_dicts.items():
+            found_module = _find_target_module(module_name, cfg)
+            for partition_spec_name, partition_spec in partition_spec_dict.items():
+                if not hasattr(found_module.module, partition_spec_name):
+                    raise ValueError(
+                        f"{found_module.module} does not have {partition_spec_name} attribute"
+                    )
+                setattr(found_module.module, partition_spec_name, partition_spec)
+
+        return cfg
+
+
 class ChainConfigModifier(ConfigModifier):
     """Chain multiple config modifiers together."""
 
diff --git a/axlearn/common/trainer_config_modifier_test.py b/axlearn/common/trainer_config_modifier_test.py
index ccfe00823..28c88c052 100644
--- a/axlearn/common/trainer_config_modifier_test.py
+++ b/axlearn/common/trainer_config_modifier_test.py
@@ -5,13 +5,16 @@
 import jax
 from absl.testing import absltest
 
-from axlearn.common import test_utils
+from axlearn.common import causal_lm, test_utils
+from axlearn.common.attention import RepeatedTransformerLayer, StackedTransformerLayer
 from axlearn.common.base_layer import RematSpec
 from axlearn.common.trainer import SpmdTrainer
 from axlearn.common.trainer_config_modifier import (
     ChainConfigModifier,
     GradientAccumulationModifier,
     MeshShapeModifier,
+    ModelConfigModifier,
+    PartitionSpecModifier,
     RematSpecModifier,
 )
 from axlearn.common.trainer_test import DummyModel
@@ -65,6 +68,88 @@ def test_remat_policy_override(self):
             _ = cfg_modifier(cfg)
 
 
+class ModelConfigModifierTest(test_utils.TestCase):
+    def test_model_config_override(self):
+        cfg = SpmdTrainer.default_config().set(model=causal_lm.Model.default_config())
+        self.assertTrue(
+            str(cfg.model.decoder.transformer) == str(StackedTransformerLayer.default_config())
+        )
+
+        cfg_modifier = (
+            ModelConfigModifier.default_config()
+            .set(
+                model_cfg_modifications={
+                    "model.decoder.transformer": RepeatedTransformerLayer.default_config(),
+                }
+            )
+            .instantiate()
+        )
+
+        cfg = cfg_modifier(cfg)
+        # The default StackedTransformerLayer should have changed to RepeatedTransformerLayer
+        self.assertTrue(
+            str(cfg.model.decoder.transformer) == str(RepeatedTransformerLayer.default_config())
+        )
+        cfg_modifier = (
+            ModelConfigModifier.default_config()
+            .set(
+                model_cfg_modifications={
+                    "model.decoder.unknown": RepeatedTransformerLayer.default_config(),
+                }
+            )
+            .instantiate()
+        )
+        # Ensure that the exception is working.
+        with self.assertRaisesRegex(ValueError, "unknown is not found in.*"):
+            _ = cfg_modifier(cfg)
+
+
+class PartitionSpecModifierTest(test_utils.TestCase):
+    def test_partition_spec_override(self):
+        cfg = SpmdTrainer.default_config().set(model=DummyModel.default_config())
+        cfg_modifier = (
+            PartitionSpecModifier.default_config()
+            .set(
+                partition_specs={
+                    "model.linear": {"param_partition_spec": ("model", ("expert", "fsdp", "seq"))},
+                },
+            )
+            .instantiate()
+        )
+        cfg = cfg_modifier(cfg)
+        self.assertTrue(
+            str(cfg.model.linear.param_partition_spec), """("model", ("expert", "fsdp", "seq")"""
+        )
+        cfg_modifier = (
+            PartitionSpecModifier.default_config()
+            .set(
+                partition_specs={
+                    "model.linear": {"param_partition_spec": ("model", ("expert", "fsdp", "seq"))},
+                    "model.unknown": {"param_partition_spec": ("model", ("expert", "fsdp", "seq"))},
+                },
+            )
+            .instantiate()
+        )
+        # Ensure that the exception is working.
+        with self.assertRaisesRegex(ValueError, "unknown is not found in.*"):
+            _ = cfg_modifier(cfg)
+
+        cfg_modifier = (
+            PartitionSpecModifier.default_config()
+            .set(
+                partition_specs={
+                    "model.linear": {
+                        "param_partition_spec": ("model", ("expert", "fsdp", "seq")),
+                        "unknown_partition_spec": ("model", ("expert", "fsdp", "seq")),
+                    },
+                },
+            )
+            .instantiate()
+        )
+        with self.assertRaisesRegex(ValueError, ".*does not have unknown_partition_spec attribute"):
+            _ = cfg_modifier(cfg)
+
+
 class MeshShapeModifierTest(test_utils.TestCase):
     def test_mesh_shape_update(self):
         cfg = SpmdTrainer.default_config().set(model=DummyModel.default_config())
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-1B-v3-flash-single-host.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-1B-v3-flash-single-host.txt
index 41971d290..063a37fd3 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-1B-v3-flash-single-host.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-1B-v3-flash-single-host.txt
@@ -114,6 +114,65 @@ mesh_axis_names[2]: 'expert'
 mesh_axis_names[3]: 'fsdp'
 mesh_axis_names[4]: 'seq'
 mesh_axis_names[5]: 'model'
+mesh_rules[0][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[0][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[0][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[0][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[0][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-1B-v3-flash.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-1B-v3-flash.txt
index a27337377..894ef8e0c 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-1B-v3-flash.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-1B-v3-flash.txt
@@ -114,6 +114,65 @@ mesh_axis_names[2]: 'expert'
 mesh_axis_names[3]: 'fsdp'
 mesh_axis_names[4]: 'seq'
 mesh_axis_names[5]: 'model'
+mesh_rules[0][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[0][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[0][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[0][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[0][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-1B-v3-single-host.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-1B-v3-single-host.txt
index 5cc38c163..0aec515fb 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-1B-v3-single-host.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-1B-v3-single-host.txt
@@ -114,6 +114,65 @@ mesh_axis_names[2]: 'expert'
 mesh_axis_names[3]: 'fsdp'
 mesh_axis_names[4]: 'seq'
 mesh_axis_names[5]: 'model'
+mesh_rules[0][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[0][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[0][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[0][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[0][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-1B-v3.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-1B-v3.txt
index 86c13eb79..d8594cb2f 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-1B-v3.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-1B-v3.txt
@@ -114,6 +114,65 @@ mesh_axis_names[2]: 'expert'
 mesh_axis_names[3]: 'fsdp'
 mesh_axis_names[4]: 'seq'
 mesh_axis_names[5]: 'model'
+mesh_rules[0][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[0][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[0][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[0][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[0][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-3B-v3-flash-single-host.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-3B-v3-flash-single-host.txt
index 32be1295c..3ea9305a5 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-3B-v3-flash-single-host.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-3B-v3-flash-single-host.txt
@@ -114,6 +114,65 @@ mesh_axis_names[2]: 'expert'
 mesh_axis_names[3]: 'fsdp'
 mesh_axis_names[4]: 'seq'
 mesh_axis_names[5]: 'model'
+mesh_rules[0][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[0][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[0][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[0][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[0][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-3B-v3-flash.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-3B-v3-flash.txt
index 3de7d2b95..0be311b31 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-3B-v3-flash.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-3B-v3-flash.txt
@@ -114,6 +114,65 @@ mesh_axis_names[2]: 'expert'
 mesh_axis_names[3]: 'fsdp'
 mesh_axis_names[4]: 'seq'
 mesh_axis_names[5]: 'model'
+mesh_rules[0][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[0][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[0][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[0][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[0][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-3B-v3-single-host.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-3B-v3-single-host.txt
index 7cc3b4afc..1373c599c 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-3B-v3-single-host.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-3B-v3-single-host.txt
@@ -114,6 +114,65 @@ mesh_axis_names[2]: 'expert'
 mesh_axis_names[3]: 'fsdp'
 mesh_axis_names[4]: 'seq'
 mesh_axis_names[5]: 'model'
+mesh_rules[0][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[0][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[0][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[0][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[0][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-3B-v3.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-3B-v3.txt
index 612565b6f..757056860 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-3B-v3.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-3B-v3.txt
@@ -114,6 +114,65 @@ mesh_axis_names[2]: 'expert'
 mesh_axis_names[3]: 'fsdp'
 mesh_axis_names[4]: 'seq'
 mesh_axis_names[5]: 'model'
+mesh_rules[0][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[0][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[0][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[0][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[0][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[0][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[0][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v1-flash.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v1-flash.txt
index 3052dab86..0c67d7a99 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v1-flash.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v1-flash.txt
@@ -185,6 +185,83 @@ mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.l
 mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.layer']['policy'].names_which_can_be_saved: '.*[kqv]_proj|.*linear1_[01]'
 mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.layer']['policy'].offload_dst: None
 mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.layer']['policy'].offload_src: None
+mesh_rules[4][1].config_modifiers[2].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[4][1].config_modifiers[3].klass: 'axlearn.common.trainer_config_modifier.PartitionSpecModifier'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][0]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][1][0]: 'expert'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][1][1]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][1][2]: 'seq'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['input_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['output_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['embedding_partition_spec'][0]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['embedding_partition_spec'][1]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][0]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][1][0]: 'expert'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][1][1]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][1][2]: 'seq'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['input_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['input_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['output_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['output_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['input_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['input_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['output_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['output_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['input_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['input_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['output_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['output_partition_spec'][2]: None
 mesh_rules[4][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v1.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v1.txt
index d57c35aea..db4233286 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v1.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v1.txt
@@ -185,6 +185,83 @@ mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.l
 mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.layer']['policy'].names_which_can_be_saved: '.*[kqv]_proj|.*linear1_[01]'
 mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.layer']['policy'].offload_dst: None
 mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.layer']['policy'].offload_src: None
+mesh_rules[4][1].config_modifiers[2].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[4][1].config_modifiers[3].klass: 'axlearn.common.trainer_config_modifier.PartitionSpecModifier'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][0]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][1][0]: 'expert'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][1][1]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][1][2]: 'seq'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['input_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['output_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['embedding_partition_spec'][0]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['embedding_partition_spec'][1]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][0]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][1][0]: 'expert'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][1][1]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][1][2]: 'seq'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['input_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['input_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['output_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['output_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['input_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['input_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['output_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['output_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['input_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['input_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['output_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['output_partition_spec'][2]: None
 mesh_rules[4][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v2-flash.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v2-flash.txt
index 605d5f326..0a90eb22e 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v2-flash.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v2-flash.txt
@@ -185,6 +185,89 @@ mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.l
 mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.layer']['policy'].names_which_can_be_saved: '.*[kqv]_proj|.*linear1_[01]'
 mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.layer']['policy'].offload_dst: None
 mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.layer']['policy'].offload_src: None
+mesh_rules[4][1].config_modifiers[2].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[4][1].config_modifiers[3].klass: 'axlearn.common.trainer_config_modifier.PartitionSpecModifier'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][0]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][1][0]: 'expert'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][1][1]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][1][2]: 'seq'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['input_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['output_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['embedding_partition_spec'][0]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['embedding_partition_spec'][1]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][0]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][1][0]: 'expert'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][1][1]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][1][2]: 'seq'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['input_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['input_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['output_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['output_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['input_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['input_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['output_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['output_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['input_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['input_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['output_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['output_partition_spec'][2]: None
 mesh_rules[4][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v2.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v2.txt
index ccf575c40..082ef5efc 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v2.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v2.txt
@@ -185,6 +185,89 @@ mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.l
 mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.layer']['policy'].names_which_can_be_saved: '.*[kqv]_proj|.*linear1_[01]'
 mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.layer']['policy'].offload_dst: None
 mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.layer']['policy'].offload_src: None
+mesh_rules[4][1].config_modifiers[2].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[4][1].config_modifiers[3].klass: 'axlearn.common.trainer_config_modifier.PartitionSpecModifier'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][0]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][1][0]: 'expert'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][1][1]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][1][2]: 'seq'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['input_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['output_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['embedding_partition_spec'][0]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['embedding_partition_spec'][1]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][0]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][1][0]: 'expert'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][1][1]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][1][2]: 'seq'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['input_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['input_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['output_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['output_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['input_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['input_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['output_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['output_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['input_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['input_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['output_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['output_partition_spec'][2]: None
 mesh_rules[4][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v3-flash.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v3-flash.txt
index e3f269bfa..9577a3439 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v3-flash.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v3-flash.txt
@@ -185,6 +185,89 @@ mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.l
 mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.layer']['policy'].names_which_can_be_saved: '.*[kqv]_proj|.*linear1_[01]'
 mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.layer']['policy'].offload_dst: None
 mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.layer']['policy'].offload_src: None
+mesh_rules[4][1].config_modifiers[2].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[4][1].config_modifiers[3].klass: 'axlearn.common.trainer_config_modifier.PartitionSpecModifier'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][0]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][1][0]: 'expert'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][1][1]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][1][2]: 'seq'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['input_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['output_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['embedding_partition_spec'][0]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['embedding_partition_spec'][1]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][0]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][1][0]: 'expert'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][1][1]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][1][2]: 'seq'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['input_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['input_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['output_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['output_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['input_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['input_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['output_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['output_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['input_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['input_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['output_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['output_partition_spec'][2]: None
 mesh_rules[4][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v3.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v3.txt
index b7457c951..ad92c6680 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v3.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-70B-v3.txt
@@ -185,6 +185,89 @@ mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.l
 mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.layer']['policy'].names_which_can_be_saved: '.*[kqv]_proj|.*linear1_[01]'
 mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.layer']['policy'].offload_dst: None
 mesh_rules[4][1].config_modifiers[1].remat_policies['model.decoder.transformer.layer']['policy'].offload_src: None
+mesh_rules[4][1].config_modifiers[2].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[4][1].config_modifiers[2].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[4][1].config_modifiers[3].klass: 'axlearn.common.trainer_config_modifier.PartitionSpecModifier'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][0]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][1][0]: 'expert'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][1][1]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['param_partition_spec'][1][2]: 'seq'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['input_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['output_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['embedding_partition_spec'][0]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.emb.token_emb']['embedding_partition_spec'][1]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][0]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][1][0]: 'expert'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][1][1]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.lm_head']['param_partition_spec'][1][2]: 'seq'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['input_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['input_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['output_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.self_attention.norm']['output_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['input_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['input_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['output_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.transformer.layer.feed_forward.norm']['output_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['input_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['input_partition_spec'][1]: 'model'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['input_partition_spec'][2]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['output_partition_spec'][0]: 'fsdp'
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['output_partition_spec'][1]: None
+mesh_rules[4][1].config_modifiers[3].partition_specs['model.decoder.output_norm']['output_partition_spec'][2]: None
 mesh_rules[4][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v1-flash-single-host.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v1-flash-single-host.txt
index 535234d6e..4aad97098 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v1-flash-single-host.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v1-flash-single-host.txt
@@ -194,6 +194,59 @@ mesh_rules[6][1][2]: 1
 mesh_rules[6][1][3]: 8
 mesh_rules[6][1][4]: 1
 mesh_rules[6][1][5]: 1
+mesh_rules[7][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[7][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[7][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[7][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[7][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v1-flash.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v1-flash.txt
index cf5ed9a88..97b025758 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v1-flash.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v1-flash.txt
@@ -194,6 +194,59 @@ mesh_rules[6][1][2]: 1
 mesh_rules[6][1][3]: 8
 mesh_rules[6][1][4]: 1
 mesh_rules[6][1][5]: 1
+mesh_rules[7][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[7][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[7][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[7][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[7][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v1-single-host.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v1-single-host.txt
index 4ec1ad578..961476a8c 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v1-single-host.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v1-single-host.txt
@@ -194,6 +194,59 @@ mesh_rules[6][1][2]: 1
 mesh_rules[6][1][3]: 8
 mesh_rules[6][1][4]: 1
 mesh_rules[6][1][5]: 1
+mesh_rules[7][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[7][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[7][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[7][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[7][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v1.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v1.txt
index a58c11472..4f8bb0091 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v1.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v1.txt
@@ -194,6 +194,59 @@ mesh_rules[6][1][2]: 1
 mesh_rules[6][1][3]: 8
 mesh_rules[6][1][4]: 1
 mesh_rules[6][1][5]: 1
+mesh_rules[7][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[7][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[7][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[7][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[7][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v2-flash-single-host.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v2-flash-single-host.txt
index 087727526..cb2898e94 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v2-flash-single-host.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v2-flash-single-host.txt
@@ -194,6 +194,65 @@ mesh_rules[6][1][2]: 1
 mesh_rules[6][1][3]: 8
 mesh_rules[6][1][4]: 1
 mesh_rules[6][1][5]: 1
+mesh_rules[7][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[7][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[7][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[7][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[7][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v2-flash.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v2-flash.txt
index 32f64479e..046e5fa16 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v2-flash.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v2-flash.txt
@@ -194,6 +194,65 @@ mesh_rules[6][1][2]: 1
 mesh_rules[6][1][3]: 8
 mesh_rules[6][1][4]: 1
 mesh_rules[6][1][5]: 1
+mesh_rules[7][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[7][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[7][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[7][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[7][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v2-single-host.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v2-single-host.txt
index d55e01b42..a56b7a38f 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v2-single-host.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v2-single-host.txt
@@ -194,6 +194,65 @@ mesh_rules[6][1][2]: 1
 mesh_rules[6][1][3]: 8
 mesh_rules[6][1][4]: 1
 mesh_rules[6][1][5]: 1
+mesh_rules[7][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[7][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[7][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[7][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[7][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v2.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v2.txt
index eb4182b28..b459bd559 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v2.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-7B-v2.txt
@@ -194,6 +194,65 @@ mesh_rules[6][1][2]: 1
 mesh_rules[6][1][3]: 8
 mesh_rules[6][1][4]: 1
 mesh_rules[6][1][5]: 1
+mesh_rules[7][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[7][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[7][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[7][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[7][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[7][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[7][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-8B-v3-flash-single-host.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-8B-v3-flash-single-host.txt
index a15dfdf0b..0273cfddc 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-8B-v3-flash-single-host.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-8B-v3-flash-single-host.txt
@@ -178,6 +178,65 @@ mesh_rules[5][1][2]: 1
 mesh_rules[5][1][3]: 8
 mesh_rules[5][1][4]: 1
 mesh_rules[5][1][5]: 1
+mesh_rules[6][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[6][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[6][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[6][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[6][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-8B-v3-flash.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-8B-v3-flash.txt
index 7f520cbde..2a7765723 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-8B-v3-flash.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-8B-v3-flash.txt
@@ -178,6 +178,65 @@ mesh_rules[5][1][2]: 1
 mesh_rules[5][1][3]: 8
 mesh_rules[5][1][4]: 1
 mesh_rules[5][1][5]: 1
+mesh_rules[6][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[6][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[6][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[6][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[6][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-8B-v3-single-host.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-8B-v3-single-host.txt
index 225299e7b..462795562 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-8B-v3-single-host.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-8B-v3-single-host.txt
@@ -178,6 +178,65 @@ mesh_rules[5][1][2]: 1
 mesh_rules[5][1][3]: 8
 mesh_rules[5][1][4]: 1
 mesh_rules[5][1][5]: 1
+mesh_rules[6][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[6][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[6][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[6][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[6][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-8B-v3.txt b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-8B-v3.txt
index 6339517df..a1fc9b8dd 100644
--- a/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-8B-v3.txt
+++ b/axlearn/experiments/testdata/axlearn.experiments.text.gpt.c4_trainer/fuji-8B-v3.txt
@@ -178,6 +178,65 @@ mesh_rules[5][1][2]: 1
 mesh_rules[5][1][3]: 8
 mesh_rules[5][1][4]: 1
 mesh_rules[5][1][5]: 1
+mesh_rules[6][0]: 'neuron-(trn2|trn2n).48xlarge-64'
+mesh_rules[6][1].config_modifiers[0].klass: 'axlearn.common.trainer_config_modifier.MeshShapeModifier'
+mesh_rules[6][1].config_modifiers[0].mesh_shape[0]: 1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[1]: 1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[2]: 1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[3]: -1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[4]: 1
+mesh_rules[6][1].config_modifiers[0].mesh_shape[5]: 4
+mesh_rules[6][1].config_modifiers[1].klass: 'axlearn.common.trainer_config_modifier.ModelConfigModifier'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].klass: 'axlearn.common.attention.StackedTransformerLayer'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.activation: 'nn.relu'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.klass: 'axlearn.common.attention.TransformerFeedForwardLayer'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.klass: 'axlearn.common.layers.Linear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[0]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear1.param_partition_spec[1]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.klass: 'axlearn.common.layers.Linear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[0]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.linear2.param_partition_spec[1]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.eps: 1e-08
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.residual_weight: 1.0
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.stochastic_depth.mode: 'row'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.feed_forward.structure: 'prenorm'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.klass: 'axlearn.common.attention.TransformerLayer'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.klass: 'axlearn.common.attention.QKVLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[0]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[1]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.input_linear.layer.param_partition_spec[2]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.key_scale.klass: 'axlearn.common.attention.ScaleKey'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.klass: 'axlearn.common.attention.MultiheadAttention'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.klass: 'axlearn.common.attention.MultiheadOutputLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[0]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[1]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.output_linear.param_partition_spec[2]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.attention.query_scale.klass: 'axlearn.common.attention.ScaleQuery'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.dropout.klass: 'axlearn.common.layers.Dropout'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.klass: 'axlearn.common.attention.TransformerAttentionLayer'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.eps: 1e-08
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.forward_dtype: 'jax.numpy.float32'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.norm.klass: 'axlearn.common.layers.LayerNorm'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.klass: 'axlearn.common.layers.StochasticDepth'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.stochastic_depth.mode: 'row'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer'].layer.self_attention.structure: 'prenorm'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].klass: 'axlearn.common.attention.GroupedQKVLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.bias: True
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.klass: 'axlearn.common.attention.MultiheadInputLinear'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[0]: None
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[1]: 'model'
+mesh_rules[6][1].config_modifiers[1].model_cfg_modifications['model.decoder.transformer.layer.self_attention.attention.input_linear.input_linear'].layer.param_partition_spec[2]: None
+mesh_rules[6][1].klass: 'axlearn.common.trainer_config_modifier.ChainConfigModifier'
 mesh_shape[0]: 1
 mesh_shape[1]: -1
 mesh_shape[2]: 1
diff --git a/axlearn/experiments/text/gpt/fuji.py b/axlearn/experiments/text/gpt/fuji.py
index 001a873e3..9a0d5179e 100644
--- a/axlearn/experiments/text/gpt/fuji.py
+++ b/axlearn/experiments/text/gpt/fuji.py
@@ -22,11 +22,13 @@
     BaseStackedTransformerLayer,
     FusedGroupedQKVLinear,
     FusedQKVLinear,
+    GroupedQKVLinear,
     GroupedQueryAttention,
     MultiheadAttention,
     RematRegexSavePatterns,
     RepeatedTransformerLayer,
     RoFormerQKVLinear,
+    StackedTransformerLayer,
 )
 from axlearn.common.base_layer import RematSpec
 from axlearn.common.config import config_for_function
@@ -38,6 +40,8 @@
     ChainConfigModifier,
     GradientAccumulationModifier,
     MeshShapeModifier,
+    ModelConfigModifier,
+    PartitionSpecModifier,
     RematSpecModifier,
 )
 from axlearn.common.utils import (
@@ -141,6 +145,21 @@ def get_trainer_kwargs(
 
     rope_theta = ROPE_THETA[version]
 
+    # TRN2 specific model config modifications
+    trn2_model_modifications = {
+        # Neuron compiler has a module to detect repeating blocks and reuse them during compilation.
+        # So compile time does not grow with the number of layers.
+        "model.decoder.transformer": StackedTransformerLayer.default_config(),
+        **(
+            {}
+            if version == Version.V1
+            else {
+                "model.decoder.transformer.layer.self_attention.attention.input_linear"
+                ".input_linear": GroupedQKVLinear.default_config()
+            }
+        ),
+    }
+
     offload_dots_saveable_policy = config_for_function(
         extended_checkpoint_policies.offload_dots_saveable
     ).set(offload_src="device", offload_dst="pinned_host")
@@ -194,6 +213,23 @@ def get_trainer_kwargs(
             train_batch_size=train_batch_size,
             max_step=max_step,
             mesh_shape=mesh_shape_from_axes(data=-1, fsdp=8),
+            mesh_rules=(
+                (
+                    "neuron-(trn2|trn2n).48xlarge-64",
+                    ChainConfigModifier.default_config().set(
+                        config_modifiers=[
+                            MeshShapeModifier.default_config().set(
+                                # TP within the chip, FSDP across chips.
+                                # Each TRN2 chip has 4 XLA cores.
+                                mesh_shape=mesh_shape_from_axes(fsdp=-1, model=4)
+                            ),
+                            ModelConfigModifier.default_config().set(
+                                model_cfg_modifications=trn2_model_modifications
+                            ),
+                        ],
+                    ),
+                ),
+            ),
         )
     elif model_size == "3B":
         trainer_kwargs = dict(
@@ -212,6 +248,23 @@ def get_trainer_kwargs(
             train_batch_size=train_batch_size,
             max_step=max_step,
             mesh_shape=mesh_shape_from_axes(data=-1, fsdp=8),
+            mesh_rules=(
+                (
+                    "neuron-(trn2|trn2n).48xlarge-64",
+                    ChainConfigModifier.default_config().set(
+                        config_modifiers=[
+                            MeshShapeModifier.default_config().set(
+                                # TP within the chip, FSDP across chips.
+                                # Each TRN2 chip has 4 XLA cores.
+                                mesh_shape=mesh_shape_from_axes(fsdp=-1, model=4)
+                            ),
+                            ModelConfigModifier.default_config().set(
+                                model_cfg_modifications=trn2_model_modifications
+                            ),
+                        ],
+                    ),
+                ),
+            ),
         )
     elif model_size == "7B":
         trainer_kwargs = dict(
@@ -325,6 +378,21 @@ def get_trainer_kwargs(
                     "gpu-(p5.48xlarge|p4de.24xlarge|a3-highgpu-8g)-(256|512|1024)",
                     mesh_shape_from_axes(data=-1, fsdp=8),
                 ),
+                (
+                    "neuron-(trn2|trn2n).48xlarge-64",
+                    ChainConfigModifier.default_config().set(
+                        config_modifiers=[
+                            MeshShapeModifier.default_config().set(
+                                # TP within the chip, FSDP across chips.
+                                # Each TRN2 chip has 4 XLA cores.
+                                mesh_shape=mesh_shape_from_axes(fsdp=-1, model=4)
+                            ),
+                            ModelConfigModifier.default_config().set(
+                                model_cfg_modifications=trn2_model_modifications
+                            ),
+                        ],
+                    ),
+                ),
             ),
         )
     elif model_size == "8B":
@@ -405,6 +473,21 @@ def get_trainer_kwargs(
                     "gpu-(p5.48xlarge|p4de.24xlarge|a3-highgpu-8g)-(256|512|1024)",
                     mesh_shape_from_axes(data=-1, fsdp=8),
                 ),
+                (
+                    "neuron-(trn2|trn2n).48xlarge-64",
+                    ChainConfigModifier.default_config().set(
+                        config_modifiers=[
+                            MeshShapeModifier.default_config().set(
+                                # TP within the chip, FSDP across chips.
+                                # Each TRN2 chip has 4 XLA cores.
+                                mesh_shape=mesh_shape_from_axes(fsdp=-1, model=4)
+                            ),
+                            ModelConfigModifier.default_config().set(
+                                model_cfg_modifications=trn2_model_modifications
+                            ),
+                        ],
+                    ),
+                ),
             ),
         )
     elif model_size == "70B":
@@ -499,6 +582,8 @@ def get_trainer_kwargs(
                     ChainConfigModifier.default_config().set(
                         config_modifiers=[
                             MeshShapeModifier.default_config().set(
+                                # TP within the chip, FSDP across chips.
+                                # Each TRN2 chip has 4 XLA cores.
                                 mesh_shape=mesh_shape_from_axes(fsdp=-1, model=4)
                             ),
                             RematSpecModifier.default_config().set(
@@ -521,6 +606,46 @@ def get_trainer_kwargs(
                                     ),
                                 }
                             ),
+                            ModelConfigModifier.default_config().set(
+                                model_cfg_modifications=trn2_model_modifications
+                            ),
+                            PartitionSpecModifier.default_config().set(
+                                partition_specs={
+                                    # Vocab parallel embeddings sharding from Megatron LM.
+                                    "model.decoder.emb.token_emb": {
+                                        "param_partition_spec": (
+                                            "model",
+                                            ("expert", "fsdp", "seq"),
+                                        ),
+                                        "input_partition_spec": ("fsdp", None),
+                                        "embedding_partition_spec": ("model", None),
+                                        "output_partition_spec": ("fsdp", None, None),
+                                    },
+                                    "model.decoder.lm_head": {
+                                        "param_partition_spec": (
+                                            "model",
+                                            ("expert", "fsdp", "seq"),
+                                        ),
+                                    },
+                                    # Sequence parallel shardings for norms.
+                                    "model.decoder.transformer.layer.self_attention.norm": {
+                                        "input_partition_spec": ("fsdp", "model", None),
+                                        "output_partition_spec": ("fsdp", None, None),
+                                    },
+                                    "model.decoder.transformer.layer.feed_forward.norm": {
+                                        "input_partition_spec": ("fsdp", "model", None),
+                                        "output_partition_spec": ("fsdp", None, None),
+                                    },
+                                    "model.decoder.output_norm": {
+                                        "input_partition_spec": ("fsdp", "model", None),
+                                        "output_partition_spec": ("fsdp", None, None),
+                                    },
+                                    # Sequence parallel shardings for feed_forward layer.
+                                    "model.decoder.transformer.layer.feed_forward.linear2": {
+                                        "output_partition_spec": ("fsdp", None, None),
+                                    }
+                                },
+                            ),
                         ],
                     ),
                 ),