Side-side jacks?
I assumed he meant some boards under the low side tires.
I just cut two length of 2x6 with a 45 degree bevel on the end.
I can see roughly how far out the trailer is in place, pull forward a couple feet, put the boards down and back the trailer up onto them.
1 board brings me up 1 1/2", if not enough add the second board.
Then the hitch jack for leveling front to back, and stabilizers to just beyond snug.
I have also used them to change a flat.
Pulled the good tire up on them, changed the flat, and drove away.
Multi purpose.