The pinbox level allows you to see how much side to side leveling is need when you park it.
I watch mine and then know which side is low and by how much.
Then I pull forward...lay down leveling boards and then back onto them.
Side to side leveling is now DONE
Then I use a 2' foot level on edge of slide out to give me an idea of how much front to back leveling I will need
Run front legs (driven section) down prior to unpinning inner section so that least amount of inner is used (smaller legs---less stable)
Then raise front high enough to unhitch...unplug umbilical cord and move truck
Then using 2' level on edge of slide out I level front to rear (raise/lower as needed)
When level f/r I then lower front 1" and raise rear stabilizers up snug
Then raise front back up to level
Provides a solid/tight level 5vr