Version 1.6.1 is The One.

Everything works, at least according to my preliminary testing. I'm going to increase the 5V buck inductor to 56µH to further reduce the ripple on the 5V line, but not in reaction to anything in particular (I have the larger one, and it's the same physical size and the reduction in current rating is insignificant).

There's inventory in the Tindie store. Go getcha one!