I have seen a few Truck Campers show up at the camp grounds and back into their assigned spot. Then lower the jacks and unhook and drive out from under their camper then lower it to the ground with the bottom supported on the ground and held steady inplace with the jacks. Alot of the area under the TC has to supported only by the jacks it seems.
Sure doesnt take them much time to stow their TC doing this - 10-15 minutes or so...
Then they have their truck available to go places in...
For security reason I don't know if I would have guts enought to run off and leave my Truck Camper sitting on the ground unattended or not. In my case it would probably grow legs and wander off on me hehe...
I have seen it done several times however... Maybe the trick is to go all the way to the ground with the rear TC body. This one setup had several short 2x12s on the ground for the TC and jacks to sit on.
ADDED NOTE: If I was going to be doing this alot I would install eyelets in the roof side four corners and run these to the ground using earth augar anchors and 1/2-inch ratchet type web straps. I already do this with my off-road camper to prevent side to side movement when the wind picks up. Easy to setup and the earth augers leave no marks in the ground when uncrewed when you leave.
Roy Ken