The first prototype of the new design arrived today!
Sadly, there was a minor manufacturing mistake. If you look between pins 11 + 12, you can see a 1K resistor array which is supposed to be a 10uF capacitor. I'm not sure how that part got switched, but it's easy enough to fix and I've already ordered one from Digikey to replace it. It'll arrive in a few days and once I replace it I'll start testing the board!