I did it and it works great.
The trick on tightening them is to do the middle ones first. And there is no need to take it easy on the middle ones. At that location, you cannot damage the frame like you can by over tightening the end jacks....Because you are lifting it where it is the strongest, and right next to where the axles are which supports the entire TT all the time. I use the middle jacks to fine tune my level. Then I snug up the end jacks. You do not need equal pressure on all 6 jacks. There is no benefit in trying to achieve that..