I received the first circuit boards from the manufacturer for verification. I found a few things, most notably that they had put the switch in backwards and that I may need to adjust my crystal parallel capacitance, but otherwise, they work great. The 3D sensing is very clean, accurate and works over a really nice distance. I tested all the other circuits and everything appears to be working, including a first for me, getting a working USB bootloader for user field upgrades. I have imagined different variations on the firmware to enable functionality like composition or extra performance features and I've planned in the ability to connect over I2C to expansion modules or other devices.  It was pretty stressful waiting for these boards to come in because it was a sizable investment. The wife never missed an opportunity to remind me.  All in all, I'm very excited to be nearly finished with this project. I've been working really hard to finish the software. This project has been by far the most difficult challenge I have ever tackled. I'm so close to success. Smells like solder.