If you do it manually it doesn't matter.
The correct camp setup is to level the coach using a bubble level inside where u can see it to get as close to level as u can get. If I am staying for more than overnight an it is far off I will roll up on boards if needed. Then deploy the self levelers. If they are working right they will level it quickly an without large movements to the coach. Shut the engine off and run the slides out.
If you do it that way you will not stress out the leveling system or the frame, seals, windows, etc on the coach. When u run the slides in and out they will go straight and seal right.
You will see a lot of mail on how the levelers pick wheels off the ground etc. Although it will do that and level the unit I have never been a big fan of over stressing the frame on a 38 foot 22,000 pound $100,000 home i paid for.