David Schwarze loves his gear-driven cam and presumably his resulting pushrods.
Notice that Porsche hasn't sold anything with pushrods since the 1976 912.  The
abundant space at the sides of the bus and Vgon engines, and the relative ease
with which a 911 (chain-driven overhead cams) engine fits, leads me to believe
that Volkswagen was keeping its engine configuration options open.
B.