Depends on your definition of ‘mount’. It wouldn’t be pretty. You will probably need to add pulldown resistors as well as the switches, and then your switch is pushing the channel high, and otherwise, it’s pulled down to 0. That would require flying leads and so forth, you’re not just going to snap them into the board. You might also consider adjusting the firmware to replace those channels with note on/off messages rather than 0/127 CC messages, which map to buttons better.
Or: you could take the source files and modify them to make the thing you want. It’s actually a reasonably straightforward modification. But there is a way to bodge it, though it’s ugly and might need a slightly larger enclosure.