So I have seriously let this project fall by the wayside. I never did get around to fixing the 5+ button problem. Construction of my new house has taken up most of my time and money for the past few months. However, we should be able to move in to the new place in a few weeks and I'll probably have some time over the holidays to work on it.
But should I not be able to fix it, I am probably going to get one of these which have become available since I started this project.
http://www.brookaccessory.com/detail/92667127/It is compatible with the MC Cthulhu so I would just remove the XBone controller PCB and plug this adapter into the Neutrik USB passthrough. Heck, I am seriously considering doing this anyway to clean up the wiring.
Anyone using any of the Brook adapters? I've mostly heard good things.