We generally put pieces of wood under the stabilizer feet. This helps to spread load and prevents "sinking" in different site soil conditions. We normally camp in "state" campgrounds where the sites are generally "natural" terrain/few "hard sites." We also keep the tongue jack well grounded and often I put a bottle jack under the A frame up front adding some side force stability. This provides marginal additional support but helps if the jack were to fail. I do suspect some movement is always probable, certainly possible.
Adam Geuss
2014 23' 23D International Serenity
2017 16' Scout
1500 Ram Laramie with the 5.7L Hemi.