Are you using the UB1 BOB with the UC300? I'm currently using a CSMIO-IP/M which forces me to use Mach3, but I have sometimes wondered about moving to UCCNC. If I then used a UC300ETH/UB1 combination, I think it would be pretty much electrically compatible with the CSMIO, differential stepper driver signalling and 24V I/O operation, etc. I believe that it can also manage slave axis homing, which the CSMIO-IP/M cannot do.