Thanks for the responses. Just a few notes...
-I am aware that I will never get the trailer rock solid, but I was hoping to get it to perform like my last one.
-I do use wheel chocks, but don't see how that stabilizes with the suspension still being active. I see these as safety items for anti-roll, but doing little to ward off up/down shake.
-I do use the orange, plastic stackable blocks, but did not use them on my last trailer. I will try the old wood blocks I used on the old one.
-I do adjust the jacks to compensate for settling. However, I have this issue on my concrete driveway as well.
-While it's possible the electric motor does not have the power to put enough pressure on the frame, I believe they do. Knowing I should not be trying to "bend" the frame with the jacks, they do set in hard and actually move the trailer up a bit when I let them dig in.
I believe it is possible that this trailer design simply has a more inherent wobble factor. My plan is to make something that will go between the axle and frame to lock out suspension jounce.
From the answers here, I think I will go back to wood bases under the jacks, minimize the extension lengths, do something that locks out the suspension, and maybe add a manual jack near the steps.
I do appreciate the many responses. If there is not one already, I'd love to see a stabilizing "sticky". There is a lot to know beyond the obvious, and I'll bet many people have improvised with great results.
