Too much power? How do you back-troll? I always keep stern into wind, both engines on and in neutral 90% of the time, then kick one of them in reverse to get the lines straightish. Which motor i shift depends on whith way the boat needs to turn(which side is going under the boat), but they are only in reverse 10% of the time. Problem I see with virtual anchors is that often backtrolling is not to keep yourself geostationary, trying to do that messes with line angles, its to keep your drift in tune with subsurface currents.
Backtrolling on a kicker SUCKS. have you tried trimming yours up a fair ways so your'e bot bouncing propwash off the transom? being centred should make it not as terrible.