I don't understand you when wroten (a reversing motor can effectively double the drive voltage.)
In my case, I have a 36-42VDC supply power to drive a VDC motor (0-36...42VDC). According your response I can't connect the 36-42VDC power supply to MD03.
Please, can you confirm this?
In this case, do you have any board to drive 36VDC motors ? (10 - 12 amp, màx.)