My code includes no keyscanning, so it doesn't know how to listen to the keybed.
If one were willing to code up the keyscanning routines, it would probably work OK (that's a guess). Obviously, you'd lose the aftertouch by using the stock keybed. The desire for aftertouch is what initially drove my whole project.
Even without the aftertouch, you'd still be able to have the portamento and fun detuning effects, but you'd need to be sure to still include the extra DAC (I got mine from adafruit) in order to get those fun behaviors.
The Mega could also become a MIDI interface to the outside world for note on/off messages. Right now, it's just setup to receive incoming messages, but a smidgen more code would enable it to send outgoing MIDI messages that you could generate based on scanning the stock keybed.
Chip