Lee parks is a giant. In all of his pictures he is grinding a knee into the ground even on the street. People with long legs can just scoot off the seat and pull that off.
Plus 1 for csmith's comment. The fastest adult mini rider in our supermoto races just sit bolt upright in the seat. He isn't really pushing the bike down or anything. Most would say his BP could be way better. But not even the kids can touch that.
Rasta just go to a z2 trackday and hangout with @
KazMan and have an instructor go out with you every session. Seriously, best dollar to learn ratio ever.