Because of their design, the newer rear stabilizers do a much better job at stabilizing if you run them down as far as possible towards the ground. A thin piece of blocking (plywood, plastic, whatever) on soft or sandy soil is all you should use. I don't use anything on concrete or very hard packed gravel.
Using multiple blocks to avoid having to run them down as far will only add to the movement we are all trying to eliminate.
Older scissor jacks are different. By design, they are more stable when they are only extended about 6-8 inches.
2016 Flagstaff 8529IKBS Diamond Package 5th Wheel
Ford F-Series SCREW 4x4
TST Tire Monitor - Sinemate 3500w Gen.
2016 Nights Camped = 42