Funny...so let's firs think about this. You hook up your trailer your front wheels are in the air, 4x4FF and I hook some pipes to the rear bumper and we lift as hard as we can to level the truck back out. Westend wants to drive away, 4x4FF and I would rather drink beer than ru n with these pipes in our hands so we chain them to the A frame of the trailer
That's your WD bars I action.
So...if all your doing is lifting the back end to level out the trailer, corecting the geometry and redistributing the load on the tow vehicle...
What will the bars do the the air bags won't ?
Exactly nothing.