Im in the same boat, Im building a Velox XL with JR 8611A servos,

while testing if one servo could over power a unpluged one the answer was yes, but the other servo the answer was NO

With the power on they worked great togeather, but one of them unpowerd the gears would bind and freze and no amount of power would move it.

I have seen peaple cut there single elevators in 1/2 just incase this did happen one side of the elevaor would still work.

I have fried 4 servos all HS5645

2 in ruder applications, and 2 in flap uses in Top Flite Corsair.

I found they do not like to be any binding unlike there anlog brothers HS645