The manual is very clear about not letting wheels leave the ground while leveling for a stay. In fact is says it so many times that the first thing I put in our storage box was 2x10s to support the tires if they did. I believe the manual.
My problem was that PT 2x10s didn't last 4 trips.
I looked at everything I could find on blocking and convinced myself that plastic blocks would fare no better.
I read on another RV sight about the horse stall liners made from recycled tires. I found and bought a 4'x6' pad at tractor supply and plotted out the best way to cut it up for use as tire blocks. They are 3/4 inch thick and will never wear out. I wore out 4 jigsaw blades cutting them to size. I can raise any two wheels on the MH 3 3/4 inches if I ever need to.
My driveway is 3 inches lower where the front wheels sit than the rear wheels. I cut the pads to fit the dual rear wheels and narrower ones for the front. The pieces vary in width by 2 inches so I can stack them and the wheels only have to step up 3/4 inches from one pad to the next.
The MH is sitting on them now and I'm out $39 for a fix that should last a very long time. The sheet was very heavy. The wide and narrow strips fit easily in the smallest storage compartment. I like doing things like this once.
My 2x10s are near the trash burn pile now because they are each in 2 pieces. I plan to raise the MH as minimally as possible because tech support at Winnie and every manual I read says to do so.