Quint.. I believe if you shot your longbows open hand you would lose it to jumping forward just like the others. That is a natural occurance from releaseing the arrow.
Shock , to me, is more from the limbs vibrating so that you can feel it, often because they are so tip heavy compared to the riser, or due to design concerns. Often because they are vibrating or hitting the end of their travel at differing times from each other Tiller being off will also accentuate the shock you feel. I believe that in almost all of the situations above, except off tiller, and maybe brace height, you can alleviate a lot of the shock by using heavier arrows, and sometimes by going to a stretchier (B50) string). This is because a heavier arrow will transfer energy to the arrow, away from the vibrating limbs. or something like that.
ChuckC