I'm not an engineer by any means, but thinking this through... the trailer's strength is derived not merely from the frame, but from the frame in concert with the monococque structure body. It is designed to be stressed with weight over the axles and the tongue, and to take torsional vector stress forward over the tongue and in a vertical motion over the suspension.
Jacking the trailer up to get the axles off the ground would entail lifting it at the jack and corners, causing it reverse stress at the axles; in other words the axles would hang off the suspended frame, and all of the weight of the trailer would be centered in the vicinity of the axles; exactly opposite of the way it was designed to handle a load.
I may be all wet with my assessment here, but it would seem to me that suspending the axles wouldn't be a good thing for the trailer.
Any other opinions?
AIR 2053 Current: 2006 Born Free 32 RQ Kodiak Chassis, & 1995 Coachmen B-van
Former Airstreams: 1953 Flying Cloud, 1957 Overlander, 1961 Bambi, 1970 Safari Special, 1978 Argosy Minuet, 1985 325 Moho, 1994 Limited 34' Two-door, 1994 B190 "B-Van"