Add air bags or air shocks to level trailer???

I suppose it's possible. You'd have to find some way to fabricate a trailing arm to connect the axles to the frame then make connections for the air bags. I don't see any way you could keep the leaf springs in service and use bags for leveling. I think the bags would fight the springs and equalizer if you had to lift one side extensively.

It's definitely a neat idea and would certainly remove the need for boards or lynx levelers to get the trailer set from side to side.