Multiple ideas:
1- The ability to apply which database is matched to on a per-season level. Some series, most notably Pokemon, would do better with this as TVDB doesn’t correctly handle above season 14 (you’re free to seek out this can of worms on your own), but TMDB does, and I have no way to apply both.
2-Manual correction for shows not in database. Say there are a couple episodes partway through a season that aren’t in a database, add a way to manually say “this is episode x in the database”. Filename labeling doesn’t always work in an appropriate manner, and removing the season/episode labeling will cause it to not show up at all (obviously undesirable).