diff --git a/README.md b/README.md
index 4efbefb..c3fede9 100644
--- a/README.md
+++ b/README.md
@@ -84,9 +84,10 @@ options:
                         Average Usage (RSS): {average_rss!S} Virtual Memory
                         Peak Usage (VSZ): {peak_vsz!S} Virtual Memory Average
                         Usage (VSZ): {average_vsz!S} Memory Peak Percentage:
-                        {peak_pmem!N}% Memory Average Percentage:
-                        {average_pmem!N}% CPU Peak Usage: {peak_pcpu!N}%
-                        Average CPU Usage: {average_pcpu!N}% )
+                        {peak_pmem:.2f!N}% Memory Average Percentage:
+                        {average_pmem:.2f!N}% CPU Peak Usage:
+                        {peak_pcpu:.2f!N}% Average CPU Usage:
+                        {average_pcpu:.2f!N}% )
   --colors              Use colors in duct output. (default: False)
   --clobber             Replace log files if they already exist. (default:
                         False)
diff --git a/src/con_duct/__main__.py b/src/con_duct/__main__.py
index 89ec63e..402aa76 100755
--- a/src/con_duct/__main__.py
+++ b/src/con_duct/__main__.py
@@ -45,10 +45,10 @@
     "Memory Average Usage (RSS): {average_rss!S}\n"
     "Virtual Memory Peak Usage (VSZ): {peak_vsz!S}\n"
     "Virtual Memory Average Usage (VSZ): {average_vsz!S}\n"
-    "Memory Peak Percentage: {peak_pmem!N}%\n"
-    "Memory Average Percentage: {average_pmem!N}%\n"
-    "CPU Peak Usage: {peak_pcpu!N}%\n"
-    "Average CPU Usage: {average_pcpu!N}%\n"
+    "Memory Peak Percentage: {peak_pmem:.2f!N}%\n"
+    "Memory Average Percentage: {average_pmem:.2f!N}%\n"
+    "CPU Peak Usage: {peak_pcpu:.2f!N}%\n"
+    "Average CPU Usage: {average_pcpu:.2f!N}%\n"
 )
 
 
@@ -648,13 +648,21 @@ def format_field(self, value: Any, format_spec: str) -> Any:
         if value is None:
             # TODO: could still use our formatter and make it red or smth like that
             return self.NONE
+        # if it is a composite :format!conversion, we need to split it
+        if "!" in format_spec and format_spec.index("!") > 1:
+            format_spec, conversion = format_spec.split("!", 1)
+        else:
+            conversion = None
         try:
-            return super().format_field(value, format_spec)
-        except ValueError:
+            value_ = super().format_field(value, format_spec)
+        except ValueError as exc:
             lgr.warning(
-                f"Value: {value} is invalid for format spec {format_spec}, falling back to `str`"
+                f"Falling back to `str` formatting for {value!r} due to exception: {exc}"
             )
             return str(value)
+        if conversion:
+            return self.convert_field(value_, conversion)
+        return value_
 
 
 @dataclass
diff --git a/test/test_formatter.py b/test/test_formatter.py
index 878c56d..642aad5 100644
--- a/test/test_formatter.py
+++ b/test/test_formatter.py
@@ -297,20 +297,51 @@ def test_summary_formatter_N_e2e_colors() -> None:
 
 @mock.patch("con_duct.__main__.LogPaths")
 @mock.patch("con_duct.__main__.subprocess.Popen")
-def test_execution_summary_formatted_wall_clock_time_invalid(
-    mock_popen: mock.MagicMock, mock_log_paths: mock.MagicMock
+@pytest.mark.parametrize("colors", [True, False])
+def test_execution_summary_formatted_wall_clock_time_nowvalid(
+    mock_popen: mock.MagicMock, mock_log_paths: mock.MagicMock, colors: bool
 ) -> None:
     mock_log_paths.prefix = "mock_prefix"
-    wall_clock_format_string = "Invalid rounding of string: {wall_clock_time:.3f!X}"
-    report = Report("_cmd", [], mock_log_paths, wall_clock_format_string, clobber=False)
-    # It should not crash and it would render even where no wallclock time yet
+    wall_clock_format_string = "Rendering: {wall_clock_time:.3f!X}"
+    report = Report(
+        "_cmd",
+        [],
+        mock_log_paths,
+        wall_clock_format_string,
+        clobber=False,
+        colors=colors,
+    )
     report.process = mock_popen
     report.process.returncode = 0
     report.start_time = 1727221840.0486171
     report.end_time = report.start_time + 1.111111111
 
+    if colors:
+        GREEN, STOP = GREEN_START, SummaryFormatter.RESET_SEQ
+    else:
+        GREEN, STOP = "", ""
+
     # Assert ValueError not raised
-    assert (
-        "Invalid rounding of string: 1.1111111640930176"
-        == report.execution_summary_formatted
+    assert f"Rendering: {GREEN}1.111{STOP}" == report.execution_summary_formatted
+
+    # It should not crash and it would render even where no wallclock time yet
+    report = Report(
+        "_cmd",
+        [],
+        mock_log_paths,
+        wall_clock_format_string,
+        clobber=False,
+        colors=colors,
+    )
+    assert f"Rendering: {GREEN}nan{STOP}" == report.execution_summary_formatted
+
+    # or if we really provide bad formatting, e.g. the opposite order of conversion and formatting
+    report = Report(
+        "_cmd",
+        [],
+        mock_log_paths,
+        "Rendering: {wall_clock_time!X:.3f}",
+        clobber=False,
+        colors=colors,
     )
+    assert f"Rendering: {GREEN}nan{STOP}" == report.execution_summary_formatted