Without question, you can use air bags and a WDH combined. I do, and have for many years and various TV's.
The WDH should be doing all the work/leveling while the air bags are at their min PSI. If not, the WDH is not set up correctly OR the WDH bars are under rated for your actual tongue weight.
Once the WDH is set right, add PSI to the bags at 5-10 psi increments. They might raise the rear slightly, but so what? The bags DO NOT transfer weight, the lift is only VISUAL.
The benefit of bags with the WDH is realized most with 1/2 tons and SUV's with soft sprung rear ends, as the bags add spring rate primary, not lift.
Again, rear end lift via the bags is visual. Leveling must be done via the WDH. But the bags do in fact add spring rate to the rear end, which I find more comfortable.
