More attempt to fix Extension after reloading

addons/io_scene_gltf2/blender/exp/gltf2_blender_gltf2_exporter.py

@@ -323,7 +323,8 @@ def __traverse_property(node):
         # I don't know why, but after reloading script, this condition failed
         # So using name comparison, instead of isinstance
         #if isinstance(node, gltf2_io_extensions.Extension):
-        if node and type(node).name == gltf2_io_extensions.Extension.name:
+        if isinstance(node, gltf2_io_extensions.Extension) \
+                or (node and hasattr(type(node), "extension")):
             extension = self.__traverse(node.extension)
             self.__append_unique_and_get_index(self.__gltf.extensions_used, node.name)
             if node.required:

addons/io_scene_gltf2/io/com/gltf2_io_extensions.py

@@ -17,6 +17,8 @@
 
 class Extension:
     """Container for extensions. Allows to specify requiredness"""
+    extension = True
+
     def __init__(self, name: str, extension: Dict[str, Any], required: bool = True):
         self.name = name
         self.extension = extension