No, those are heavy and expensive if you stacked them to get the height you need. Generally you do need a bed mat or horse stall pad as a good means to keep the camper from sliding around though. Although have to take into account what you’re padding it up with.
My reccomendation was the “blue or pink” foam sheets. Comes in different psi compressive strengths. If you get 40psi foam it won’t crush at all. Even 10psi would probably work under that lightweight camper but less durable over time.
Although a wood frame would be perfect too like stir crazy recommended.
You can build the frame tight so it won’t slide and will be cheap and effective. Then a thin sheet of plywood (or not depending on how much support the floor needs) and a stall mat or bed mat on top and you have a permanent solution.
Hell, with a light weight pop up and minimal storage, if height allows, you could build a bit taller frame, say 6” or whatever and leave the back end open for shallow storage space (fishing poles, skis, shovel etc)