After our first two new to us MH's and not having auto levelers. Now our 3rd one having them.
I can't imagine going back to one without them !
Yeah the first two did the cut the boards, plastic lego blocks that cracked/split etc, trial and error to finally get the rig level only to hear the Mrs saying quit moving around while she's doing her makeup etc.
I tried to add a couple of the scissor jacks to the rear of our second MH with was a pain since there were limited places to actually mount them.
Now we pull up , push a button it self levels, I plug in the shore cord, wife hits a button and out comes slides and runs out the electric awing and we're set up in less than 5 minutes.
As for why do people put blocks under the leveler pads ? Some CG's their place their rules...