Believotron synthesizers with the Axoloti core hardware should be compatible with the same list as the core itself. Some work will need to be done to map individual keys and controllers to the software models. http://community.axoloti.com/t/usb-midi-controllers/19
We have specifically tested the following controllers and have reported no problems:
Akai MPK Mini MK II
Novation Launchpad Mini
Arturia Mini Lab
We have tested these controllers and found problems:
Novation Launchkey Mini: The knobs overload the midi messages
We are happy to test any controller if you would like to ship it to us. Please simply message @DazzlingDuke and we can get something set up.