Is more safe to do manual disposing internally.

src/RhinoInside.Revit.External/UI/UIHostApplication.cs

@@ -9,21 +9,14 @@ namespace RhinoInside.Revit.External.UI
   using Autodesk.Revit.ApplicationServices;
   using External.DB.Extensions;
 
-  public abstract class UIHostApplication : IDisposable
+  public abstract class UIHostApplication
   {
     protected internal UIHostApplication(bool disposable) => Disposable = disposable;
 
     #region IDisposable
 #pragma warning disable CA1063 // Implement IDisposable Correctly
     readonly bool Disposable;
     protected abstract void Dispose(bool disposing);
-    void IDisposable.Dispose()
-    {
-      if (!Disposable) return;
-
-      Dispose(disposing: true);
-      GC.SuppressFinalize(this);
-    }
 #pragma warning restore CA1063 // Implement IDisposable Correctly
     #endregion
 
@@ -37,7 +30,17 @@ void IDisposable.Dispose()
     public abstract UIDocument ActiveUIDocument { get; set; }
 
     #region Runtime
-    internal static UIHostApplication Current;
+    private static UIHostApplication _Current;
+    internal static UIHostApplication Current
+    {
+      get => _Current;
+      set
+      {
+        if (_Current == value) return;
+        _Current?.Dispose(true);
+        _Current = value;
+      }
+    }
 
     internal static bool StartUp(UIControlledApplication app)
     {

src/RhinoInside.Revit.External/UI/UIHostApplicationConstrained.cs

@@ -14,9 +14,12 @@ public UIHostApplicationConstrained(UIControlledApplication app, bool disposable
     {
       _app = app;
 
+      if (!disposable)
+      {
 #if REVIT_2023
-      _app.SelectionChanged += SelectionChangedHandler;
+        _app.SelectionChanged += SelectionChangedHandler;
 #endif
+      }
     }
     protected override void Dispose(bool disposing)
     {

src/RhinoInside.Revit.External/UI/UIHostApplicationUnconstrained.cs

@@ -36,7 +36,7 @@ protected override void Dispose(bool disposing)
           _app.SelectionChanged -= SelectionChangedHandler;
 #endif
           _app.ViewActivated -= UpdateOpenViewsList;
-          _app.Dispose();
+          //_app.Dispose();
         }
 
         _app = null;