[Bug] Undo does not delete material after copy and past object form other Rhino session

I’m copying and passing objects from one rhino to others.
After a Past, if I make an Undo, the imported material is not deleted.

Fortunately, there are a lot of tools for finding deleting the material.

Hmm - yes, I see. Could almost be a feature.

RH-58432 Undo is partial