So I bought my parts and finally got them all. Without further delay (not including the nine hours I spent) I soldered everything together. This is my second time soldering, so everything was quite time consuming, especially the smaller MCP23017 pads and the SMD diodes I convinced myself to use, but I finally got it done. Also checked most–but not all–of the connections with a multimeter. Now I start work on the ZMK firmware!!! And hopefully finally get it working.

Also, we got OG rgb– glow in the DARK keycaps