I pulled the trigger and ordered PCBs and parts - so far everything except the displays. I've made a number of PCBs in the past ~15 years since I got into the electronics. Frequently I have made some silly mistake that has necessitated my ordering a new variation of a board. Of course every time I do it I try to be extra meticulous so as to not repeat the problem. As an abundance of caution, I ordered just 10 PCBs.

I decided to implement a button (again, inspired by Tom Nardi's Cyberdeck SAO) for stand-alone interaction. Initially I was going to try to do this as a capacitive touch pad, but I've had mixed success with those in the past and space was already tight. This button is connected to the GPIO2 pin on the header so it could be triggered from whatever its attached to. The SAO header  also implements a pair of  i2C pins. I like the idea of there being an API to draw on the screen, but that necessitates writing an i2C software stack to handle the second i2c.

Now I just have to wait for all the parts to get here. I'm not in a rush, and it's still a few months until SuperCon, so its going to be a couple of weeks. After I've successfully assembled a board, I can order the remainder of PCBs and all the displays.