That’s pretty sick, gonna look into it

I’d say it’s likely possible, depends also on OS.

Yeah. In a sense, laptops do it all the time.

I used to run both an old nvidia and amd card to drive two separate displays. One was the primary/gaming card and the other would drive youtube/netflix/etc. It worked pretty well but was a little buggy. Switching tabs with web players from one screen to the other sometime broke playback and would require a refresh.