I use Anderson Jack Blocks. They work very well. I have 4 of them. 90% of the time they are on the jacks on either side of the wheels. I use one or two LEGO blocks under the front jacks.
I’ve had a couple of camp sites that I had to use the blocks under the front jacks.
I’ve also had maybe 2 sites that were horribly in level side to side. In that case one side of my wheels were lifted off the ground. So I manually leveled the coach by raising the off the ground wheel’s respective jacks a bit and placed LEGO blocks under the tires, let the jacks back down so that the tires were not off the ground.
In my opinion the Anderson Jack Blocks are indispensable. Plus they are wider which gives the jacks stability being shorter and the wider on the ground. Also they are magnetic and very easy to use.
