Do the VersaPlanetary gearboxes have a ball bearing at the input and output ends? If they do, all the side loads put on the shaft by the wheel would be taken by the ball bearings. The motor shaft would then only transmit torque and would not experience any side loads.
I think the shooter team were able to get about two dozen launches before burning out the rear bearing of their mini-CIM. One of them suggested buying a whole bunch of motors and swapping them when they burnt out.
Neither the sponsoring teacher nor any of the mentors went for that idea.