Has anyone used this product to stabilize their camper when off the truck? It's a bit pricey, but looks like it works. Thanks. https://www.stablecamper.com/stablization
You will find more gadgets available, but for my 12' campers, I was using only front support. 4x4 sitting horizontally on cut to size 4x6 or cinder block. Later on I found aluminum 4x3 tubing for lighter weight. Not only stabilized the camper very well, but also supported the weight of fresh water tank on front.