Good question. I was thinking mostly of preventing wing down groundloops and loss of control. There, having a pogo stick that lets one wing be, say 3 feet off the ground and the other up lets you keep upwind wing down. Directional control is usually by rudder, not putting a wing down -- that's when you lose control!
Such pogo sticks need not be at the tips. They could be attached mid span.
But I like the jets idea. Since this is about preventing a rare loss of control event, you don't need much. But you do need some -- maybe 100 lbs of force for a few seconds. And how do you keep it from getting too much momentum and pushing the other wing down -- needs delicate control.
Wing drops on takeoff are a continuing problem at conteststs. Yes it's minor, only one major incident so far (tonopah), but that's more because we are careful to keep spectators out of the way of the errant gliders.