Hardness nowadays is not a major contributing factor to the arc. There are hard rubbers that have high throw yet also there are hard rubbers that have low throw.
https://ooakforum.com/viewtopic.php?f=56&t=35851&fbclid=IwAR2P_QeFc6fgU754l0T55ZzCP-aR3hgddHSVqAZxmbyX1-C7eV0nld7svuM
OOAK forum had a chance to ask some questions about DHS and its products. This is a good read though take it with a grain of salt.