I don’t think you would need to hack the keyboard, most of those parameters are controllable via MIDI. So you could either use or build a midi controller that is assignable or can be assigned to parameters you wish to control. I have an Arturia Keylab Mk2 which I use to control my Genos via my DAW. The Genos has a number of features that can be triggered by pedals or external midi messages. Not sure about all of the mixer features on the Genos, I haven’t examined the midi message requirements for those but I would expect they are able to be externally controlled - either via CC messages or Sysex. Unfortunately my Keylab Mk2 doesn’t send out sysex but it wouldn’t be impossible to build something with a microcontroller or source a suitable controller that could do that. Not sure though why you want to do that, as the Genos controls are really nice to use - the OLED display also helps see what they are controlling along with the bank controls. You can definitely control the style parts and accompaniment via a midi controller though, and my midi controller has 5 pedal inputs (not that I would ever remember in a performance what my feet had to do on 5 separate pedals!)
Simon