keyboard-diy VS Framework-13-Vanilla-Reconstruction

No IO expander needed. My board is 5x6 each side so 11 wires are routed from one side to the other to make a combined matrix of 5x12. I counted 14 wires in USB-C, allowing larger boards like 7x7 or 6x8. It's all hand-wired and the build log is at https://github.com/macroxue/keyboard-diy

Also, have you checked ergodox? Dactyl? https://github.com/topics/ergonomic-keyboard looks like what you search for, random link was sending me to page https://github.com/macroxue/keyboard-diy

In a previous post https://www.reddit.com/r/ErgoMechKeyboards/comments/qsr8mg/minimalist_highangle_tenting/, I had only a bridge piece connecting the two split boards. The structure sits on the table but it can't be lifted up as the two splits will just slip out. In this post, the three additional pieces, especially the white bar in the middle, push the two splits outwards. The tension prevents the splits from slipping out when the board is lifted. Please see https://github.com/macroxue/keyboard-diy for the build log and 3D-printed models.

I've built split keyboards with one Teensy controller and one USB-C cable connecting the two splits. Please see https://github.com/macroxue/keyboard-diy for the build log. It might give you a few ideas.

If you want the ortholinear layout, maybe the Darknight: https://github.com/macroxue/keyboard-diy

RedBaron: a tented split by u/macroxue with documentation & STL files.

I open up my Framework often enough that I'm considering just removing the captive screws. (I open it for taking measurements, mostly) On most laptops, this would be a problem, but Framework has those magnets keeping the Input Cover in place. I've forgotten to tighten the screws before taking the laptop to school/work, and I haven't had any issues when that's happened. But there's always the possibility that I'm missing/forgetting something.

I've been working on a 3D model of the Framework 13 so that myself and others could use it for a base when developing mods. You're welcome to contribute if you'd like, or to use it to make your own mod.

Point those engineers and students to this project: https://github.com/Captain-Pumpkinhead/Framework-Vanilla-Reconstruction

No reason you couldn't mod the chassis yourself. Matter of fact, I'd love to help you do that. I've got a GitHub repository where I'm trying to reconstruct the Framework 13.5" chassis in FreeCAD. After we have that, it would be trivial to print a taller bottom chassis so that we could make the new modules fit.