What games specifically? I’ve never encountered that. I think what you are seeing are games that switch from 240p to 480i.
Yes that’s what I meant. From the PS1 logo at boot up to the game menu to the actual game, I feel like the console switch back and forth between 240p and 480i several times. I don’t recall ever encountering that on Saturn.
Regarding Snes, is there a way to force it to work on most screens even without the dejitter board?