Phil, I have yet to encounter such a challenge... just lucky I guess. As noted the most blocks I have ever had to use was 2 high usually under one side {under both rear wheels on that side} and once an a while one or two under one of the front wheels but blocks are cheap and I have more then I've ever needed.
I've got a couple under one side of my cargo trailer as one wheel sits in the gravel with the other up on my newly paved asphalt driveway. I have another under the tongue jack sitting on a 2 X 10. Never had Leggo's as a kid, too old I guess but I keep finding ways to use them now and I am almost 69.
:B