[HO455]

In 2 words Freemont Bridge.
I commute across it and it has large expansion joints as well as traffic grooves worn into the surface. Before I cut the cups I would be at 80 psi at ride height. But to comfortably drive across the bridge I needed to raise the pressure about 10 psi. By comfortable I mean without the front end bouncing up and down excessively on each joint. (The shocks are fine I just don't like the 1960's Cadillac kind of ride.) Bumping the pressure up cures the up and down action, but too much pressure and then the truck starts to wander in the grooves. I believe the wandering is from the alignment no longer being correct with the front end raised. That's the reason I didn't remove more than 1/2 " I want to see how it behaves before committing to a full inch.
This is one of the things I never realized about air bags. The range of pressures you can drive on is fairly wide but the pressure where works well is very narrow. In my truck 3 psi off of optimum makes a big difference on how it feels to me. So I feel the trick is to figure out what that optimum pressure is then adjust the bag mounting to get that pressure at the ride height you desire.