I printed out a version of design 1 and the hybrid one. I had the thought of making the side pieces removable, which would mean less 3d printing. I tried this with the design 1 print on the right. I'm instantly abandoning that idea. I have to deal with more screw holes and it's a pain. Maybe for a finished product it could be multiple possible side pieces and people could print what they want. This would also address the right/left handed issues with a controller design.

Anyway, I was pleased with how the left one came out. I learned that I did not give myself enough room to mount the buttons and analog stick. I'm looking at different options. I think I can find a more appropriate analog stick than the one I currently have.

The size overall seems about right. Maybe a little small, but that should be better when expanded for mounting the components.