Two things jump to mind. The second levelling system first!
The fully automated system appears to rely totally on just the corner steadies. Surely, you should always raise a caravan by its suspension, i.e. under the wheel otherwise you are putting undue strain on the chassis.
Secondly, I like the idea of the inflatable bag, but I wonder how long it will be before the bag starts to perish. Secondly, I notice the company only issues phone numbers and have no address displayed on their website. That one always makes me dubious. The mechanics too spring to mind. Unless the bag is fully inflated, which according to them is up to six inches, then surely there must be some movement in a bag inflated say to 2.5 inches as the whole thing by nature is flexible.
For a time, I had one of the milenco levellers, and found that, unlike on a ramp where the caravan was lifted vertically, the milenco tried to push the van against the opposing wheel giving us the situation where the floor would creak continually and sometimes, we couldnt close doors properly. That one was soon confined to fleabay.
To my mind there are many many caravan gadgets out there that perhaps require a little lateral thinking before one buys them.