just for spit & grins, here's a little tidbit form Jobst Brandt's blog, where he mentions that the finned "heat sink" pad bodies actually do nothing practical:

"Talking to the KoolStop people at the annual bicycle trade show, I
learned that it is a KoolStop formulation and that they make pads for
most of the smaller brand brakes, including Matthauser. You might
recall that the Matthauser brake pads had cooling fins on the rear.
This was as scientifically incorrect as the compound. Effectively no
heat passes through the brake pad that is an insulator. The heat must
go into the rim to be dissipated."

As with all things Brandt and Controversial: YRMV. (but what he says here makes sense to me)