[Montellese]

Android TV is problem because have only 2GB RAM...now i Have Kodi Leila 18.9 and PlexKodiConnect addon and work good...because cant add manual series and movies in library i play direct from Plex.
Once i try to put complete over 250k movies and series to library...almost 4 hours (my internet speed 600/60). Almost 7GB metadata and Android start to work very slow... I restart TV but still working very slow so i delete all library...

Wow that's a lot of metadata

I hope that you find a way with Playlist ... 

I had a quick look at playlists and the available API and it probably won't work. The problem is, that playlists are only based on videos or music and there is no distinction between movies or episodes. There is also no hierarchy like tvshows and seasons.

And maybe if you look addon video pseudo library (not work in Matrix)
https://forum.kodi.tv/showthread.php?tid=205148

...it work with Leila and I can import what i want from Plex in my movies and series folder...I must manually rename files and create folder and then work from library...

It uses the STRM workaround which can also be a problem for some devices because it results in creating and modifying a lot of files on the filesystem which may result in corrupted SD cards etc.