Sync Watched only (not un watched)

[rEs-84]

Is there a way to sync only watched status, rather than the full watched/unwatched status of each file.
I've split out mine/ my partners library's to make it easier for her to find her odd show among all mine.
With the intention of regular syncing.

But if we watch one of her shows on my account, i'd like to just sync that watched status.
But not overwrite all the rest. Ie not to mark lots of her's unwatched just for a single watched episode

thanks in advance

[rEs-84]

actually, testing again has shown different results for me.
I could of sworn, if i un watched something on ID1, then synced to ID2. ID2 would have it unwatched.

I thought it was a full sync of one ID's watched/unwatched status to the 2nd ID.

Is that the case or is a merge (ie updates both ID's)?