We are looking for application where we need sometimes backdrive DC-motor manually. In order to protect motor driver and rest of the electronics we're thinking of electrically disconnecting motor leads from the motor driver using FETs or relays. Is there something else you should worry about? E.g. if rotating motor shaft too fast will produce too much voltage and we damage something inside motor or damage FETs isolating it? Is answer different for brushed and brushless motor?
Motor is rated for 24V, 5A continuous, 10A peak for 2 seconds. It's geared 50:1, so we can potentially backdrive it quite fast.