When I park the coach for an extended time, I always dump the air. Sometimes I lower the jacks to take some weight off the tires, sometimes I don't.
When I don't dump the air, sometimes over an extended time a ride height valve can leak a little and let one corner of the coach sit down, while the other corners are still up. Looks ridiculous, and it can't do the coach any good.
2016 Creekside 23RKS
2012 Ram 2500 Laramie 4X4 Cummins 6.7L