Gary,

I believe our air bags have internal rubber bump stops in the base so when the bus is all the way down that is what is supporting the chassis.

Except when I have it up on stands for servicing, I drop it all the way down and have done so for as long as we have owned a coach. If it hurts anything i am unaware of it.

I also have to lower the front all the way down to get it in the garage and after getting the first 10 feet out of the garage I have to raise the front all the way up. If exercising the air bags is bad I am not aware why.