Levelers/Chocks/Blocks/Jacks

I'm a believer that if you need two wheels a side to carry the load, you should support each one.

That is the safest way of thinking for sure.

Difference between two tires to carry the load where there is heat build up while rotating down the road and sitting still. If you check with the tire manufacturer for load capacity at very slow speeds or sitting still where you don't have heat build up, you will find it is more than capable of one tire carrying the load.

However, if you do decide only one is going to be blocked, I would block the inside wheel to reduce the loading on the axle shaft. But even the axle is strong enough to be supported by just the outside wheel because it is designed for the dynamics forces of bouncing over the bumps and dips of the road.

I gave up on the stackable lego blocks, many swear by them

Trick I've found is unless you are using on smooth asphalt or concrete, you must use a board under them to provide a smooth service. I've been using the same set for 12 years and only have two cracked, both from before I learned this trick and used them on ground which had pieces of rocks in it. Even the two which have cracked are still useable, I just don't use the cracked side to pull up on them. That said, I do prefer my old school wood blocks which are much cheaper and easier to replace.