The old Hannibal (heavyweight) setup misfired all the time, because there was no buffer the FP gas just hit the Alpha valves pushing the valves shuttle up and firing the flipper. And since the bottle in that one wasnt a screw valve a misfire was pretty much a guarantee unless you did the gassing up just right. So to make sure this wasnt a problem we placed a long 2x4 piece of wood between the arm and the base of the robot keeping the arm in the up position. So if the ram did misfire it would hit nothing. The problem was solved with the introduction of a buffer tank and a screw valve in the bottle anyway but we kept the gassing up process that way. With the feathers we do the same thing.

All in all it is a matter of what the tech checker and the roboteers agree is the safest solution for a particular robot. If you are not sure whether or not you should place a locking device, well place one anyway. It doensnt count in the weightlimit and Id rather have one safety feature too many than be one safety feature short.