Since Stan has a molded
fiberglass mini-motorhome, I don't think he'll be using a tongue jack any time soon.
With a motorhome, if any leveling needs to be done, it should be by driving wheels onto leveling blocks. After the coach is level, the stabilizers can be snugged up under the frame at the rear corners to stop bouncing from the vehicle's suspension. The stabilizers are not intended to actually lift the coach for leveling purposes.