How about storing on a water bed?
I for one can't believe that storing or transporting a Hobie on 2" to 3" OD PVC parallel pipes is not safe.
My 2013 PA-14 has been stored on my Hobie Trailex trailer, with parallel 2.9" OD, schedule 40 PVC pipes, set on cross supports 67" apart AND allowed to "sag and conform to the hull shape" for now 6 years. I slotted the PVC so it will move and sag, conforming to the hull shape. The PA-14 is a heavy Hobie.
I have not seen any issues with the floor/deck buckling or changing shape. My "loaded with gear" PA-14 is about 180 pounds and the PVC conforms really well to the hull.
I snug fit and do not cinch down tight, the safety straps on my PA to the trailer while on the road and make sure the straps are loose once back home.
For a lighter weight Hobie, I would use 2" OD schedule 40 PVC.
This photo, shot from the stern, shows how the PVC sags and conforms to the PA-14 hull shape.