We seem to have a related issue with smart playlists and the way MusicBrainz and Plex are handling identical recordings over here: https://forums.plex.tv/t/problem-with-treatment-of-same-song-on-multiple-albums-plex-music/480148/12
I see how this is intentional in terms of cataloging the music, counting plays and sharing ratings, and personally, the shared play counter or rating isn’t the issue here either. The issue lies in the way Plex adds all copies of the same recording to the smart playlist, even though it really would make sense to just have one copy, since it is after all the same recording, if you get what I mean?