Inflatable amas
 

Why not inflatable amas on a trimaran so when the folding structure is
folded in for trailering the amas deflate.

Or, have the inflatable amas have a rigid spine and have them held out
by wire/rope/etc fixed to the mast top, bottom of keel, stern and bow
so they are rigidly held in place. A couple of struts keep them held
out. Disconnect these and the amas deflate and there is no folding
structure.