If you have a standard heavy duty frame, using the two corner jacks (if you HAVE jacks and not stabilizers) would most likely be ok.
HOWEVER, if you have an Ultra-Lite type frame you will most certainly twist it even if you have jacks instead of stabilizers.
You will tell it is twisted when you can't open or close doors and drawers.
I would still use leveling blocks to do side to side and the front jack (or landing gear on a 5th wheel) to do the fore and aft.
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW