If this comes through, and works, I would buy a HHKB for this. This would make pretty much the perfect keyboard out of the HHKB, especially for those of us who like having quick USB 3.0 ports available, or use their keyboard with a laptop with limited Usb ports (2 for me).
I wish more build it yourself MX case/PCB designs were designed with extra ports, and based around USB-C; For my use case, at least, it increases the versatility of the board.