I think using axolti to control modules is the way to go, mount it in a rack panel and add lots of CV and gate outs, a few ins, a display and some rotary encoders and it could be used as a master control for the whole rack, incorporating several modules in one
MIDI in/out, that already supports MIDI over usb and a range of existing controllers.
A stereo sound source that could be programmed to be a clone of any other DSP based module
ie OSC, effects, I'm thinking mutable instruments gear here, Clouds, Braids etc.
Gate/trigger controller similar to the Octocontroller, or monome's control modules.
All in one open platform for a fraction of the price.