Both comments are correct. Your parking brake is set via the transmission and this locks the drive wheels, which I do believe are the rear wheels. Lifting either of the wheels will provide you with less "parking" brake. This isn't the end of the world as you can chock the fronts to make sure they don't move. What I would suggest, and what I have my father do, is once in the sight, check for level. My father has the auto leveling system so he has a digital indicator saying he may be 3 degrees out of level one way. He has learned just how far out of level he can go without picking up the tires. My point is that you should try to get the rig fairly leveled without the use of the jacks and use boards or blocks under the tires first to try and eliminate the tires from being lifted.
I don't feel that it will be a huge deal to camp like that on occasion but over time I could see that doing damage to the suspension, pull a brake line off or any number of things... un likely damage will occur but it is possible. One other reason I have my father keep the tires down is so that no one can come and steal the wheel! Again un likely, but could happen...
TV- 2015 Ram 2500 CCLB 6.7 Cummins 3.42 gears
Camper - 2015 Saber 322BHTS