"bow shock" or "hand shock" is the prime result of bow and arrow issues, and maybe operator issues. in the order of propelling an arrow, the bow limbs are the engine, the bowstring is the transmission and the arrow is the vehicle.
if the string MATERIAL is hmpe polyethylene, it has far less elasticity than dacron polyester. SO, if you spin up a string and twist up another string of the SAME fiber, there should be no difference in the "hand shock" category - you either gots some or you don't.
BUT, if you go from dacron to hmpe there IS a possibility that the less stretchy fiber IS in some part responsible for the "shock", because you probably will need a different spine and/or heavier mass weight arrow as dictated by the higher performance of hmpe fiber.
but a string TYPE being responsible for "hand shock" - uh uh, not gonna happen, i've never seen any physics to prove that out. if you think that's yer problem, look elsewhere for the culprit.