Deleting a material set from a type now also purges usages from type instances

src/ifcopenshell-python/ifcopenshell/api/project/append_asset.py

@@ -11,7 +11,12 @@ class Usecase:
 
     def execute(self):
         self.added_elements = set()
-        if self.settings["element"].is_a("IfcTypeProduct") and not self.file.by_guid(self.settings["element"].GlobalId):
+        if self.settings["element"].is_a("IfcTypeProduct"):
+            try:
+                self.file.by_guid(self.settings["element"].GlobalId)
+                return
+            except:
+                pass
             return self.append_type_product()
 
     def append_type_product(self):