If user deletes a tag in OPDM that already exists on a drawing. It would be nice if the PID drawing was flagged as requires syncronizaion or not up to date and when user opens the drawing in OPPID, it would show that drawing is not up to date and data has been modified in iTwin.
At the moment we can only delete tags that are not used in PID.
I would strongly suggest if we make it possible to delete a Tag in OPDM that is actually used that there is a message popping up warning user that this tag is used on a PID or in 3D. Then maybe another message do you really want to delete?