On Hackster.io, Jeremy Cook, writes about the Harmonicade, a modular 5.5 (x2) octave, multi-channel MIDI keyboard which uses arcade-style push-buttons arranged in the Wicki-Hayden button layout.
Like Dvorak layouts, this alternate note arrangement is much less common. As seen in the demo video, however, KOOP Instruments has leveraged the Wicki-Hayden setup to create a stunning dual-pad instrument that looks like a lot of fun to play. The dual input pads are entirely modular and plug into a central control unit using DB25 connectors that are wired to the buttons in a matrix.
The central board contains a Teensy 3.6, plus a number of additional buttons and knobs for control over the sound. After being properly translated, digital audio signals are passed along via a MIDI jack.
On the KOOP Instruments site, the have all of the CAD files, project code, and build instructions you need to create your own Harmonicade.