Changing Media Types Within Same Library

[jellyfin]

Short answer: No.  Mixed libraries are not well supported to begin with and are strongly discouraged.  Movies should be in a movies library and shows in a shows library.

I, and it seems a lot of other people here, keep our Anime separate from our western shows.  So our setups looks something like this in terms of libraries.

Movies (non-Anime movies)
Anime Movies
TV shows (non-Anime shows)
Anime

I have lots of "Nature" DVDs and BDs, like "Planet Earth" or "Wild Afrika", where some have several episodes and some are just one movie.

I used to add them to a "mixed" library, but from what you wrote, I should split them into two libraries?
Those with multiple episode into a "Shows" and the others into a "Movies" library? Or do you think that the one-episode movies could also work in a "Shows" library? It would be strange to have them totally separate.

I already noticed that Swiftfin iOS does not support mixed libraries either.