All the above is what my 2004 HWH system does, but there will come a day when you also need to dump the air to get under a tree branch or a 12-1/2 foot overpass.
Also, you have to dump before leveling so your jacks can reach the ground. And with big RVs you have to be careful to not over torque the big box on uneven ground... if you choose to use jack pads.
I sometimes will drive my tires up on those corrugated-squares and then use a jack pad.
* And if you ever get stuck in the mud or beach sand, you will also need those jack-squares to shove under your driver's side tires. That and with a prayer you might be able to avoid a tow!
* This one time, I tried doing a U-turn around a farmer's bard in Iowa... In THE RAIN, and I got stuck on the wet grass. So don't do that. Stay on pavement when it rains or wait until the rain goes away for 12 hours before you pull away from you boondocking spot, so the ground can absorb the water.