I have been pulled up on 2 skis on my 96 XP. Pulled me up no problem, and wasn't out of control when I went side to side.
But it is illegal in most places to ski with only 1 person on the ski, and one in the water.
I found that it IS legal here, as long as I have mirrors, but they have to be 3"X4" and I am not sure if they are that big.
Basically, most places require the ski to be big enough to haul 3 people...one driver, one spotter, and the exhausted skier once he goes down.