So, the air bags are lifting the rear of the truck higher than normal?

How does it do in the alternate height setting???

Mine rides great, loaded or unloaded.

 

I don't know what normals really is. When it's on auto level, it will automatically adjust to whatever the load is to a predetermined height set at assembly factory. As loaded, it sits about an inch an a half higher than the front. Measurements taken from top of hub to bottom center of fender.The other option is to turn it off which sets it in alternative height. This is to be used when towing a trailer and lowers it by about an inch and a half. Dealer says if not pulling a trailer I need to leave it on. I wished I had some of your luck. It's a miserable drive.

 

The air suspension system is always on auto level, there is no off during normal operation. Alternate ride height just levels out the ride height, but it still auto levels, as in when loaded higher it pumps the bags up more to maintain its height setting.
I run mine at normal ride height all the time anymore, loaded, towing or empty and, as I stated above, mine rides just fine at all times.

Anyway, I'm not sure how you are determining that the bags on your truck are fully pumped up at your current loaded weight.
If you are just going by how hard the bags are when you try to press against the side, they will always seem very hard as even unloaded they have quite a bit of air pressure in them just to support the weight of the truck itself.