Actually, if the elevator servos stay neutral while the plane is rolling, they drain current trying to stay neutral. MAYBE current is slightly different in both setups but IMO nowadays, we carry a lot of battery capacity aboard.

This kind of mix seems not to be good on all planes at least from my experience and smokingcrater's...

On IMAC rates, when doing a snap roll, one of the elevators stay neutral (about) and the other moves about twice the throw of elevator alone. One thing to note, a plane setup for 3D in smaller scale aerobats is most likely tail heavy so elevator throws are very modest for normal flying...