Here are the classic Reform keyboard design topics I found:
The pocket keyboard is really constrained. I messed about for a while, trying to add some angle to the hands and standard choc key spacing. The simple thing is to repurpose the trackball keys for typing modifiers. Better thumb keys would need a new top.
I ended up with this asymmetric design, where the bottom row is probably replacement trackball mods. I shifted my right hand into the center to get enter and | on the far right. It would be easy to tilt the centre column vertical for a not very ergo set of Atreus style thumb keys. I’d rather keep the number row and rely on chording the trackball keys.
How much clearance is there between the top of the keyboard PCB and the inside of lid? (How much vertical space is there for switches and keycaps?)