Although I had manually filled air bags that could have raised the rear suspension enough to engage my lower StableLoad wedges, I found it was quicker to just roll out my shop jack and lift the the receiver slightly rather than pull the air hose over from the compressor or run a smaller compressor off the truck. If you don't have a shop jack or you have on board air, using your air bags to do this works well.
I don't think they will eliminate much more than 1" of sag, but they will will firm up the ride when you are loaded.