there is a section in the owners manual that expressly says you should not do that. yes you can lift the coach, and many people do, but its not safe, or good business practice.
the reason is liability. what happens if the jacks fail and some one is injured?
there is a real danger of that happening.
why did they have YOU run the jacks instead of them? because they can say you did it, thats why. it transfers liability.
if this sounds alarmist, thats ok. better you have the information than not. what you do with it is your business.
as i've said before, you own the jacks. do what you feel is right and safe.
