Vertical screen with horizontal games

[mickmaster]

I just bought a new 32" 16:9 lcd IPS monitor to switch out my older 21" 4:3 lcd monitor in a custom arcade cabinet I built . My plan is to mount it vertically so the older vertical arcade games are larger and horizontal games are roughly the same size as before. I figured out how to change the config to rotate the screen and I have two questions.

Question 1: Is there a way to force 4:3 for emulationstation? It's very difficult to read because of the font size and it just doesn't look right on a vertical screen in 16:9.

Question 2: Horizontal games in 4:3 have terrible lag with the vertical screen. The worst is nes games. I'm using a rpi3 with the latest recalbox. Is this fixable? I read something about changing GPU memory as a possible fix.

Thanks for your help.