I'm going to get hammered for this (I have been before), but here goes.
Stabilizer jacks are NOT "leveling" jacks.
OK, that's out of the way.
First, until you take virtually all the load off the trailer suspension and tires...both of which are very 'flexible'...you'll have movement. Short of putting the thing on blocks, there's a limit to what you can achieve.
The Lippert accessory rods will address side-to-side movement (as illustrated), but will do zero for fore-and-aft movement...again as illustrated. The depiction covers one dimension but not the other. Half a loaf, or you buy two and apply one side-to-side and the other on another jack fore-and-aft. Or spend $500+ and buy two sets and install them in both directions. Maybe.
Perhaps all that's overkill. Here's where I get my butt kicked. I, like many, use a cordless drill to raise and lower the jacks. I have a pretty good drill, so I lower them on high speed, then, I shift the drill to low gear and add about an inch or so of lift on the "low" side of the trailer first. I rarely am able to get the trailer perfectly level side-to-side, so I use that as an opportunity to slightly jack the trailer on the low side to get closer to level. THEN I use ONLY high speed on the drill to lower the jacks on the "high" side of the trailer. By staying in high gear, the drill does not have the oomph to "jack" the trailer and throw it out of level. I can move the bubble about one mark on the Hopkins level. In other words, just a little. https://smile.amazon.com/Hopkins-085...+trailer+level
I like the Hopkins, because it has a straight edge on the bottom that lines up with the bottom of the frame and makes it a snap to install.
THEN I go to the tongue jack and add a couple of cranks to take up the slack and square up the door frame of my HW PUP.
Yep...NOT INDICATED. Breaks the rules. And works like a charm. My PUP is quite stable and level, because a bit more load is on the hard points and not just the tires and suspension. Cranking the tongue jack "by eye" to square up the door opening is also important, because a typical PUP frame is about as stiff as overcooked spaghetti. You can open or close the top of the door opening at least an inch using the tongue jack after setting the stabilizer jacks. And once the rear stabilizer jacks are set, torquing the tongue jack does little to throw the trailer out of level, but it does wonders to bend the frame and adjust the door opening.
By the way, if you have a caster wheel on your tongue jack, consider replacing it with a pad like this: https://smile.amazon.com/Standard-Tr...J7ZH8ESZAXG543
I like this one, because it can save your bacon when you have a high lift or low lift to get level.
The caster wheel does nothing to reduce movement in any direction, even if in something like this: https://smile.amazon.com/Camco-44632...5%3A2470955011
I have the wheel dock, and I love it, but the tongue jack is as flexible as a wet noodle, so in addition to replacing the caster with a foot, the shorter the tongue jack (less cranked down) the better, so put some solid blocking under it to shorten the shaft extension. https://smile.amazon.com/Valterra-A1...5%3A2470955011
Just be sure to leave plenty of up/down movement to reconnect the ball if you approach at a different angle when you hookup after the weekend.
Being "level" means a lot, because "most" of the loads are vertical. I use a leveling wedge on the downhill tire, and if I must, I dig a hole for the uphill tire, but I get the bubbles on the Hopkins levels as close to center as possible. My wedge: https://smile.amazon.com/Camco-44573...ailer+leveling
Anderson makes something better but more expensive: https://smile.amazon.com/Andersen-Hi...ailer+leveling
If I had it to do over, I'd buy the Anderson.
There's one time this method does little to help. In "intimate" situations, the whole camper becomes a reenactment of "if this van's a-rockin', don't come a-knockin" but we all have our little crosses to bear.
As I said, the vertical loads are taken care of very well, but the side-to-side stuff is another matter.
Turns out, however, that normal day-to-day life applies few side-to-side loads on the RV.
The scissors jacks under the trailer are little different than the scissors jack that came with my truck to change tires, so they are quite capable of lifting a heavy load...2000 pounds or more. The problem is the frame, which is "mild steel". "Light" and "strong" are incompatible, so you must used good judgement when you add a bit of "lift" on the stabilizers. If you use your factory-supplied hand crank, it's EASY to overdo the lift. The strength of your wrist to resist twisting as the drill does its work helps limit how much torque you can apply. But I experimented with the hand crank, and I assure you that I could crank the jack right through the floor of the camper with that crank. Caution is advised.
Except as noted, my PUP is adequately stable, and as with how much torque I apply to the jacks, a bit of discretion in the other matter also does wonders to avoid attracting unwanted attention.
Let the butt kicking begin.