This case for the Helix keyboard has optional legs that can be removed and even stored in the top row. There are spots for rubber feet that are a radius of 6.5mm (13mm edge to edge).

I added a protection edge to keep the acrylic from getting banged around in a bag.

When printing the feet use Place on face on the end that would touch the desk. It's a small surface area so use skirts if you need extra stick to the print bed.

The screw heads are M2 with a counter sink for the head so even without rubber feet the keyboard will lay flat.

The Acrylic for the display is raised a bit as I installed the pro-micro as a hotswap DIP socket

Here is a video from Ergohaven on how that's done.

Filament in photos is Hatchbox Dark Green PETG & Paramount 3D Stealth Gray PETG.