Since someone else just tried to start a similar thread and it got locked, I’ll add a bit to this one.
It occurred to me recently that Plex apparently already handles this with multi-part video files, since the documentation requires that both files have the same audio and subtitle tracks. The bare minimum would be to apply this to TV series, without having to change the UI at all. Just remember what the audio/sub setting was on the last watched episode in a series (or even season) and apply it to future episodes.
I get that it’s likely to break, like a show that has a commentary track for only a few episodes, but dealing with that would be the exception. Maybe just have a toggle for sticky language settings for TV shows.
