I don't have triple axles, but I have used those anderson camper levelers and they are the best thing ever. Only a couple of cases where I had to have a nice long 2x6 to put under the tires first, then use the levelers on it, due to wet soggy ground.
We have a 2x6 long enough to go under our wheels with 45 angle on the ends.
1) Park where we want to setup.
2) 2 foot level across the floor, measure how much out. (say 3/4 inch)
3) Multiply by 4 will give how much out in the trailer width. (3 inches)
4) Move forward or back and build a 3" tall platform with the 2X6
5) Move the camper up on the platform and install the X-chocks.
Perfect side to side every time. Have even set up on an incline and made the platform level front to back.
Our block collection contains 1/4" to 3 1/2 (4x4s) all cut to the same length to construct whatever we need.