Blocks under Level-Up feet?

For me, it depends on the site. For example, right now we have a couple of plastic blocks under the left side. There is a depressions on the left side and without the blocks, the auto system wanted to raise the right side wheels off the ground.(Go figure!) So I put the blocks under both left side rear jacks (one each). Now all wheels are down and we are level. I like to keep the wheels down on the ground for the added stability.

If the site is fairly level with no depressions, I just let the auto system do its thing. Had good luck with that approach.