I see most of the portable console projects use the PS1 screen and thought that if a bigger screen had a case with a slot(dock?) made for it then you can mod the consoles into a case(kinda styled like an MVS cart) that would have a universal plug/s for rca`s and power but original gamepad port(or could there be a universal controller?) as well as somewhere to put cart or disc. Just throwing this in the air.
Might be problems with different power specs between consoles?? Maybe a 6 pin plug where certain pins have different power ratings.
So you can have a few different consoles that plug into one screen with no visible cables connecting them to the screen.