Duplicate and Sync diagram objects

I would like to copy the content of one diagram to another diagram object, changes made in one should be reflected to the other only for few nodes and links. (i.e) Let’s say we have 3 nodes and 3 links in one diagram, when i create a copy of it, i want only 2 nodes and 2 links to be present in the new diagram object. Also any changes made to those 2 nodes and links should be reflected in both diagrams.

To achieve this, i have shared the same model object among those two diagrams and achieved the sync between all the nodes and links. To remove the sync for a specific node and link, i have changed them to unmodeled parts, which served the need. But am not able to link these unmodeled nodes with another ummodeled/modeled nodes with a link. (Issue #1)

Another issue is, while referencing the same model the custom routes are lost (Issue #2) i.e. I’ve linked two nodes and set the custom routes between them, now as i switched from one diagram to another I am able to see routes as I had set in diagram1 but if I update the routes in diagram2, diagram1 is not getting updated with same points. I would like to have both diagram in sync when I update either of them.

Is there any way to solve these issue? or do you recommend any other approach to achieve this need?

I would think that the easiest solution would be to have two Diagrams both showing the same model. In Diagram #2 you would use a different template that would control which Layer the Part was in. And you could make one such NodeLayer and one such LinkLayer to be completely transparent.