I'm not sure if I would be able to add a feature like that, but custom texture and music support will definitely be included! Perhaps I'll still look into trying to add that, though.
Viewing post in Baldi's Fun New School Ultimate comments
Or, perhaps I could make it so you could use video files (such as an .mp4) from your device for the cinematics, and you could just select what video file you want to use for an intro (or outro) to your custom floor from ones that you could maybe put in some "cinematics" folder of sorts. I think that could work, but I'll have to do some testing like what I did with the custom texture and music support.