There’s already an existing suggestion asking for Plex not to show multiple instances of the same movie/episode in Continue Watching if they’re available in multiple libraries. Please comment/vote in that thread in order to help us avoid distracting or cannibalizing votes.
Unless I’m missing some unique aspect of your suggestion I’ll close this thread as a duplicate.
An alternative might be to consolidate your different libraries (e.g. using the Categories tab to display a filtered version of the library.
