Thanks for the reply Jesse. Yes, that was me that left a voice message for you earlier. My last post vanished; I posted twice, talking about the Workman layout, and how similar it is in principle to the way you designed your keyboard.
By "new chair", I was also including "stand up desk" if that appeals to you.
Sorry to hear about the risk of splitting the design now. I remember in an earlier version you did have it split completely. Making it modular, perhaps even putting the logic and controller into a third unit, would make it pluggable. For instance, the ErgoMagic has a number-pad you can plug in as well.
I do appreciate the art you put into the design; I suppose the splitting of the top plate is minimal risk, the risk is in the electronics connections, especially over a 5 foot run?