Joe do you read blogs on this site?
Dans lifting set up is not that much different than what I did for a couple of years, and what Eric does.
Eccentric strength ability is a very large determining factor in the jumps. How much force you CAN NOT handle during a high speed take off will change the speed of take off and force produced at take off dramatically.
Eccentric training places a huge amount of tension on the muscles and so does Isometric training. More tension and stresses on the muscles has a positive effect on development over time.
Like i’ve said many time. Joe you are stronger than probably every long jumper in the world. However, LJ is more of a speed and power discipline than a strength discipline.