This forum isn’t used much and has an uncleared SPAM post, but I’ll write this anyway.
I love my Xkey 37. It sits on permanently on my desk either in front or behind my wireless computer keyboard depending on what I’m doing.
With the move to Bluetooth, I hope that you are also considering the possibility of a modular system where multiple units can attach together, e.g. a base unit and an extension (or even two). It would only require a slight redesign of the right end of the base unit–simply change the high C key to a normal shape, with the right edge of the unit notched appropriately. The extension could just snap in, and with wireless the units wouldn’t need to be connected electronically.
Put that on Indiegogo and I’m in.