High wind and the truck camper

The jacks are more stable (wider stance) than blocks by quite a bit. But they aren't strong enough to stand up to the sheer forces - not designed for that. Once a jack begins to bend, it's tip very quickly. That's why I suggest (and most manuals do to) keeping the weight on stands, but keeping the jacks touching the ground. The stands keep the sideways load off the jacks, the jacks keep it from tipping over.