Sid, I'd put a PTC in series with that Canon motor. I've had three Legacy locomotives come in at various times with shorted Canon motors, two of the three smoked the RCMC, the 3rd I was able to replace the FET and rescue the RCMC. I'd be looking for around a 2A trip PTC, that will give you peak current of 3 amps or more to the motor for 20-30 seconds, more than enough for any normal running.
The RCMC does sense motor overloads, but Jon Z. informed me that a total short was not always detected and could indeed cook the RCMC, and I have living proof that it can happen, multiple times!
The Canon motors are junk, and I'd reconsider the idea of using it.