I'm having issues with the D-pad, it doesn't have enough room and it doesn't stick out enough which makes it feel odd.
I found a way to solve both these problems. I'm gonna use 2x 1mm polycarbonate sheets instead of 1x 2mm.

(I used flashy colors for illustration purposes, it's gonna be transparent)

This way the D-pad sticks out 1mm more and has 1mm more room on the inside. As an extra bonus the screen will have more room aswell.

After this is done the buttons should feel just like a SNES controller.