I use a one foot square , double layer , 3/4" plywood pad under the leveler pads, to spread the foot print , and keep the metal pads off, and from sinking into, the ground.
Depending on the ground you may need to re-level as the levelers sink in.
DW has a marble she sets on the counter once a week or so to check level and tell me when to re-level. My system allows me to touch each leveler to re-level so I don't need to fully retract and start over.
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.