2013 28BH here.
2013 28BH here and I can relate. I will share what I did and I can say I am more than pleased with the results.
1) $5.00 Yellow chocks from Walmart. After you are leveled side to side, hammer one on each of the frt of frt and rear of rear. A small sledge will help set them firm.
2) The X chocks don't spread far enough for our wide stance axles. Pick up Fastways One Step Chock.
http://www.fastwaytrailer.com/shop/onestep-chock/
3) Get yourself a couple of 2"x10" boards and cut the into 18"-24" pices. Tie together 2 and 3 boards so you have 1, 2 and 3 high blocks. Use these in appropriate heights at the 4 corners. The higher you can keep the stabilizer contact point, the better.
4) Buy, or assemble a 18"-24" 10"x10", use this under your tongue.
the reason for the 18"-24" lengths is the larger footprint, the greater stabilization.
I am pretty pleased as we have 2 Collies 80 and 90 pounds, a 3 yr old, the wife, and myself and movement is definitely at a minimum. I may try slide jacks, but was tols they can negatively impact slide operation if too much torque is applied to them.