diff --git a/tools/gltf_auto_export/auto_export/get_collections_to_export.py b/tools/gltf_auto_export/auto_export/get_collections_to_export.py
index 969c0de..fe110f3 100644
--- a/tools/gltf_auto_export/auto_export/get_collections_to_export.py
+++ b/tools/gltf_auto_export/auto_export/get_collections_to_export.py
@@ -27,17 +27,27 @@ def get_collections_to_export(changes_per_scene, changed_export_parameters, blue
 
         for scene in library_scenes:
             if scene.name in changes_per_scene:
-                print("scanning", scene.name)
                 changed_objects = list(changes_per_scene[scene.name].keys())
                 changed_blueprints = [blueprints_data.blueprints_from_objects[changed] for changed in changed_objects if changed in blueprints_data.blueprints_from_objects]
-                print("changed_blueprints", changed_blueprints)
                 # we only care about local blueprints/collections
                 changed_local_blueprints = [blueprint for blueprint in changed_blueprints if blueprint.name in blueprints_data.blueprints_per_name.keys() and blueprint.local]
-                print("changed_local_blueprints blueprints", changed_local_blueprints)
+                # FIXME: double check this: why are we combining these two ?
                 changed_blueprints += changed_local_blueprints
 
-        print("CHANGED BLUEPRINTS", changed_blueprints)
-    
+        # dealt with the different combine modes
+        if collection_instances_combine_mode == 1: # 0 => split (default) 1 => Embed 2 => Embed external
+            # we check for object specific overrides ...
+            filtered_changed_blueprints = []
+            for blueprint in changed_blueprints:
+                blueprint_instance = blueprints_data.internal_collection_instances.get(blueprint.name, None)
+                if blueprint_instance:
+                    combine_mode = blueprint_instance['_combine'] if '_combine' in blueprint_instance else collection_instances_combine_mode # FIXME! yikes, should be "split"
+                    print("combine mode", combine_mode)
+                    if combine_mode == 0: # we only keep changed blueprints if mode is set to split (aka if a blueprint is merged, do not export ? )
+                        # but wait, what if we have ONE instance of merge and others of split ? then we need to still split !
+                        filtered_changed_blueprints.append(blueprint)
+
+            changed_blueprints =  filtered_changed_blueprints
         blueprints_to_export =  list(set(changed_blueprints + blueprints_not_on_disk))
     
     # changed/all blueprints to export     
diff --git a/tools/gltf_auto_export/auto_export/get_levels_to_export.py b/tools/gltf_auto_export/auto_export/get_levels_to_export.py
index 33a23b8..0c885e2 100644
--- a/tools/gltf_auto_export/auto_export/get_levels_to_export.py
+++ b/tools/gltf_auto_export/auto_export/get_levels_to_export.py
@@ -2,44 +2,38 @@ import bpy
 from ..helpers.helpers_blueprints import check_if_blueprint_on_disk
 from ..helpers.helpers_scenes import (get_scenes, )
 
-def changed_object_in_scene(scene_name, changes_per_scene, collections, collection_instances_combine_mode):
-    print("BLAAAAAAAAAAAAAAAAAAAAAAAAAAAAH", scene_name, "combo mode", collection_instances_combine_mode, "changes", changes_per_scene, "collections", collections)
-    # TODO: IF collection_instances_combine_mode is not 'split' check for each scene if any object in changes_per_scene has an instance in the scene
+# IF collection_instances_combine_mode is not 'split' check for each scene if any object in changes_per_scene has an instance in the scene
+def changed_object_in_scene(scene_name, changes_per_scene, blueprints_data, collection_instances_combine_mode):
     # Embed / EmbedExternal
     if collection_instances_combine_mode == 0: # 1 => Embed
         return False
-    """if scene_name in list(changes_per_scene.keys()):
-        print("here", scene_name)"""
+
+    blueprints_from_objects = blueprints_data.blueprints_from_objects
+
+    bluprint_instances_in_scene = blueprints_data.blueprint_instances_per_main_scene[scene_name]
+    changed_objects = [object_name for change in changes_per_scene.values() for object_name in change.keys()] 
+    changed_blueprints = [blueprints_from_objects[changed] for changed in changed_objects if changed in blueprints_from_objects]
+    changed_blueprints_with_instances_in_scene = [bla for bla in changed_blueprints if bla.name in bluprint_instances_in_scene]#[blueprints_from_objects[changed] for changed in changed_objects if changed in blueprints_from_objects and changed in bluprint_instances_in_scene]
+    
+    level_needs_export = len(changed_blueprints_with_instances_in_scene) > 0
+    print("changed_blueprints", changed_blueprints)
+    print("bluprint_instances_in_scene", bluprint_instances_in_scene, "changed_objects", changed_objects, "changed_blueprints_with_instances_in_scene", changed_blueprints_with_instances_in_scene)
+
+    return level_needs_export
 
 
-    for scene_name_current in list(bpy.data.scenes.keys()):
-
-
-        for object in bpy.data.scenes[scene_name_current].objects:
-            print("foo", changes_per_scene[scene_name_current])
-            if object.instance_type == 'COLLECTION':
-                collection_name = object.instance_collection.name
-
-            if object.name in list(changes_per_scene[scene_name_current].keys()):
-                print("changed object", object.name)
-                return True # even a single object is enough to flag the scene
-
-
-# TODO: this should also take the split/embed mode into account: if a collection instance changes AND embed is active, its container level/world should also be exported
+# this also takes the split/embed mode into account: if a collection instance changes AND embed is active, its container level/world should also be exported
 def get_levels_to_export(changes_per_scene, changed_export_parameters, blueprints_data, addon_prefs):
-    print("TOTOOO")
     export_change_detection = getattr(addon_prefs, "export_change_detection")
     export_gltf_extension = getattr(addon_prefs, "export_gltf_extension")
     export_models_path = getattr(addon_prefs, "export_models_path")
     collection_instances_combine_mode = getattr(addon_prefs, "collection_instances_combine_mode")
 
     [main_scene_names, level_scenes, library_scene_names, library_scenes] = get_scenes(addon_prefs)
-    # or changed_object_in_scene(scene_name, changes_per_scene, collections, collection_instances_combine_mode)
  
-    # print("levels export", "export_change_detection", export_change_detection, "changed_export_parameters",changed_export_parameters, "export_models_path", export_models_path, "export_gltf_extension", export_gltf_extension, "changes_per_scene", changes_per_scene)
     # determine list of main scenes to export
     # we have more relaxed rules to determine if the main scenes have changed : any change is ok, (allows easier handling of changes, render settings etc)
-    main_scenes_to_export = [scene_name for scene_name in main_scene_names if not export_change_detection or changed_export_parameters or scene_name in changes_per_scene.keys() or not check_if_blueprint_on_disk(scene_name, export_models_path, export_gltf_extension) ]
+    main_scenes_to_export = [scene_name for scene_name in main_scene_names if not export_change_detection or changed_export_parameters or scene_name in changes_per_scene.keys() or changed_object_in_scene(scene_name, changes_per_scene, blueprints_data, collection_instances_combine_mode) or not check_if_blueprint_on_disk(scene_name, export_models_path, export_gltf_extension) ]
 
     print("main_scenes_to_export", main_scenes_to_export, changes_per_scene)
     return (main_scenes_to_export)
\ No newline at end of file
diff --git a/tools/gltf_auto_export/helpers/helpers_blueprints.py b/tools/gltf_auto_export/helpers/helpers_blueprints.py
index 3f9eb1d..42ac9ea 100644
--- a/tools/gltf_auto_export/helpers/helpers_blueprints.py
+++ b/tools/gltf_auto_export/helpers/helpers_blueprints.py
@@ -215,6 +215,9 @@ def blueprints_scan(main_scenes, library_scenes, addon_prefs):
     internal_blueprints = []
     external_blueprints = []
     blueprints_per_scenes = {}
+
+    blueprint_instances_per_library_scene = {}
+
     for blueprint in blueprints_per_name.values():
         blueprints.append(blueprint)
         if blueprint.local:
@@ -223,9 +226,12 @@ def blueprints_scan(main_scenes, library_scenes, addon_prefs):
                 if not blueprint.scene.name in blueprints_per_scenes:
                     blueprints_per_scenes[blueprint.scene.name] = []
                 blueprints_per_scenes[blueprint.scene.name].append(blueprint.name) # meh
+
         else:
             external_blueprints.append(blueprint)
 
+    # we also need to have blueprint instances for 
+
     data = {
         "blueprints": blueprints,
         "blueprints_per_name": blueprints_per_name,
@@ -236,10 +242,12 @@ def blueprints_scan(main_scenes, library_scenes, addon_prefs):
         "external_blueprints": external_blueprints,
         "blueprints_per_scenes": blueprints_per_scenes,
 
-        "blueprint_instances_per_main_scene": blueprint_instances_per_main_scene
+        "blueprint_instances_per_main_scene": blueprint_instances_per_main_scene,
+        "blueprint_instances_per_library_scene": blueprint_instances_per_library_scene,
+
         # not sure about these two
-        #internal_collection_instances,
-        #external_collection_instances
+        "internal_collection_instances": internal_collection_instances,
+        "external_collection_instances":external_collection_instances,
     }
 
     return SimpleNamespace(**data)
diff --git a/tools/gltf_auto_export/helpers/helpers_scenes.py b/tools/gltf_auto_export/helpers/helpers_scenes.py
index 4b66fe9..e163768 100644
--- a/tools/gltf_auto_export/helpers/helpers_scenes.py
+++ b/tools/gltf_auto_export/helpers/helpers_scenes.py
@@ -94,7 +94,7 @@ def copy_animation_data(source, target):
 def duplicate_object(object, parent, combine_mode, destination_collection, blueprints_data, legacy_mode, nester=""):
     copy = None
     internal_blueprint_names = [blueprint.name for blueprint in blueprints_data.internal_blueprints]
-
+    print("COMBINE MODE", combine_mode)
     if object.instance_type == 'COLLECTION' and (combine_mode == 'Split' or (combine_mode == 'EmbedExternal' and (object.instance_collection.name in internal_blueprint_names)) ): 
         #print("creating empty for", object.name, object.instance_collection.name, internal_blueprint_names, combine_mode)
         collection_name = object.instance_collection.name
@@ -102,6 +102,7 @@ def duplicate_object(object, parent, combine_mode, destination_collection, bluep
 
         object.name = original_name + "____bak"
         empty_obj = make_empty(original_name, object.location, object.rotation_euler, object.scale, destination_collection)
+        
         """we inject the collection/blueprint name, as a component called 'BlueprintName', but we only do this in the empty, not the original object"""
         empty_obj['BlueprintName'] = '"'+collection_name+'"' if legacy_mode else '("'+collection_name+'")'
         empty_obj['SpawnHere'] = '()'
diff --git a/tools/gltf_auto_export/tests/test_change_tracking.py b/tools/gltf_auto_export/tests/test_change_tracking.py
index bf2f948..89facef 100644
--- a/tools/gltf_auto_export/tests/test_change_tracking.py
+++ b/tools/gltf_auto_export/tests/test_change_tracking.py
@@ -209,7 +209,7 @@ def test_export_change_tracking_custom_properties_collection_instances_combine_m
         file_path = pathlib.Path(file_path).stem
         mapped_files_to_timestamps_and_index[file_path] = (modification_times_first[index], index)
 
-    # now add a custom property to the cube in the main scene & export again
+    # now add a custom property to the cube in the library scene & export again
     print("----------------")
     print("library change (custom property)")
     print("----------------")
diff --git a/tools/gltf_auto_export/todo.md b/tools/gltf_auto_export/todo.md
index 0063bb5..cdbd5bf 100644
--- a/tools/gltf_auto_export/todo.md
+++ b/tools/gltf_auto_export/todo.md
@@ -30,14 +30,16 @@
    - [x] get_source_scene                             => remove, unused 
    - [x] assets_list["BlueprintsList"]
       BLUEPRINTS LIST {'Blueprint1': [], 'Blueprint6_animated': [], 'Blueprint4_nested': ['Blueprint3'], 'Blueprint3': [], 'Blueprint7_hierarchy': [], 'External_blueprint': [], 'External_blueprint2': ['External_blueprint3'], 'External_blueprint3': [], 'Blueprint8_animated_no_bones': []}
-
    - [x] internal_collections => replace with "internal_collections" or "local_collections"
    
-
+- [ ] fix COMBINE MODE passed as int instead of enum value
 - [x] move all things that alter data "permanently" to pre-save
    - [x] lighting/ scene components injection
    - [x] blueprintNames ?
    - [x] or more simple: just remove them after save as we do for others: lighting_components
+
+   - [ ] if we want the blueprintsList / future paths of blueprints to be present inside external assets, we are going to need to keep them around, ie: inject them in pre-save & not remove them 
+
 - [ ] update cleanup_materials
 
 - [ ] remove bulk of tracker related code