The build institutions are on the mentioned GitHub and I have a build video here: https://www.youtube.com/watch?v=K5RpbYzx7gw&ab_channel=PolyKybd
If someone is interested in the kit, you can also pre-register: https://www.crowdsupply.com/polykybd/polykybd
Well right, you can spend 400$ on a keeb without a single display and no custom software. As mentioned, I plan for a kit ( https://www.crowdsupply.com/polykybd/polykybd ), as I don't want to assemble all the boards and it will be the fun parts for those who buy one.