I'd also thought about the getting a set of those 3-wheeled furniture movers to put under the jacks just to allow that little nudge you often need to get the camper centered. Hopefully sometime this year I'll have a concrete floor under the camper. For general storage/moving I'd prefer a frame of some sort that supports the tub, not just the jacks, with wheels under that. Problem I'm having is finding a set of wheeled movers with the appropriate weight rating.
For those concerned about lateral forces being exerted on the jacks, check out this video.
Loading a truck camper, by HalmarkRV:E