And there’s a feature suggestion discussing for Plex to add a similar solution to their products.
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.
Beyond that, as @Rickt1962 pointed out, you can already cover some of that e.g., using smart playlists/collections…
