I do the same as Mary...EXCEPT on both sides of the wheel
. I only have one axle
and the full 10-block stack of "Legos". I love'em. I too will lay an extra (or two depending on how many you have to level with) on each side of the blocks and use my usual plastic chocks. It's worked well for 6 yrs.
I'm also with Haggy (Radar) that you only should have to level one wheel from left to right...then of course the bumper jack to level fore and aft.
What ever you do, do NOT level with "leveling" jacks installed on the trailer unless they're designated to. I had an instance (and saw another in 2015) where I was relying too much on my leveling jack. It put my 13' Scamp
in a bind and caused the A/C's fan to "scrub"!!
After releveling and taking most of the pressure off the leveling jacks, it stopped. Again, at Piney in Oct of 2015, I saw this happen on a new 2015 16' Scamp
. A gentleman was asking me about it. I told him when he let it down and hooked it up to the tow, to test the A/C before unplugging the power. He did and it stopped his scrubbing as well... two totally different A/C units - Coleman and Dometic.
Good luck as this was one if not the most frustrating tasks of my trailer- until my blocks!! The (Bal) is good...just wont work for me.