It would be great if you could implement the full search features TMDb has — filters for region, type of release, language, rating, number of votes, etc. Maybe a “TMDb
movie search” & “TMDb TV search” in the search tab similar to the custom filter — sorry but the custom filter doesn’t cut it.
The TMDb search is the only one I’ve found that allows a user to really eliminate the junk when searching for new movies or TV shows to watch. Every other “discovery” is littered with tons of anime, 10 star rating with one to ten votes, etc — stuff that has a small and specific audience, and I’m not interested in wading through every time I want to do a discovery for new material.
Currently TMDb search is what I use, but it makes it a pain to move from the the site to the app because the app syncs with trakt — tmdb sync is to basic, I’m sure that’s due to TMDb’s APIs and how they’ve chosen to imponent things — as they told me, they see themselves more as a source of information than a tracking platform 
Anyway, IMO this would be the best discovery search available to bring in and refine a search that then allows the user to tie it into their trakt or Moviebase account. If the API is available for that
but at least it’s clearly possible.