[DanBrowne]

Our team had the same problem. We love the ball-shifters, but the output shaft problem is one of the VERY few cons, if not the only one.
We discovered the issue a few weeks before our first competition. Our initial solution was to put one layer of electrical tape on the output shaft and hammer it back into place.
When this solution failed at Championships, we had the machine shop put roll pins into the output shaft. This worked amazingly. When we got our ball-shifters this year, we made this modification before we put the gearboxes together. Zero issues so far, and I don't expect any.