Raising camper height...wood/foam/rubber etc...

I also have used the pink foam from HD on two different truck campers successfully for several years. I have always used the two inch. My present camper really only needs 1/2 - 3/4 inch for adequate clearance. I have always put the foam directly on the bed and it fits itself and conforms to the ribbed bed surface. Has anyone used 1/2 or 3/4 foam? If so, how has the thinner sheets held up?