It's generally a bad idea to clamp on WilderNests, so I would have assumed the same for the FlipPac.
The mounting surfaces are fiberglass, typical shell clamps crack the fiberglass if you tighten them enough to keep it from shifting and the foam seal tends to walk out. Also when deployed not all of the clamps are doing equal work, so the force is disproportionate. Again, using the WilderNest, when flipped open and two people (about 350 lbs) sleeping on a 4' lever, there's around 1,000 lbf on the non-hinge side mounting rail. It's distributed along the 6' length, but I still use 6 x 5/16 bolts (3 per side). Also think about off highway or even just rough roads, a 300~400 lbs camper is definitely going to want to move with vibration and in an accident, those little clamps aren't going to do much to hold the camper.
I'll use them to transport a new 'Nest, but I bolt them on ASAP. I had a 'Nest once that looked like someone took bites out of the right side (non-hinge) side from the clamps. Now this was after 15 years, though.