Changing shape isn't deleting the old part

Changing a shape with having the former shape not as RootObject doesn't delete the old shape. This is because in json_part: "root_objects = list(active_document.app_active_document.RootObjects)" doesn't delete objects not on the root object layer

What is the wanted behavior here?:

• Replacing "RootObjects" with "Objects" then correctly delete all old objects
• A more non destructive way could be to actually replace the objects with: getObjectBy... methods to only delte the old objects (and the sheet?) and then create the new object (at the same position in the object hirachie?)