I took the time to level really well so the bubble level in the fridge was perfect. Then I put a good blob of silicone adhesive beside my cup holder and set a bubble level in it, adjusted to show level. Now I just use that bubble when camping. I used those angles to calculate how far out I can be on the wheels and it was an inch and a half. So I carry pieces of plank and one 3/4 inch board. But usually I can get it close enough just wiggling around a bit in the site.
The most inconvenient thing is stopping for shopping or food. It can be tricky to find a level spot to park or to remember to turn Mr Fridge back on when leaving. Someone should make a device that chirps when out of level.