A thicker BASE gasket means...
... a little LESS low end (because of a little less compression)
... but a little MORE top end (exhaust and transfer port timing duration is longer).
Most base gaskets are made of a cardboard type material.
(and a base gasket made from a 'cereal box'... say... will work OK in many cases... but I coat them with grease and let the grease soak in for a while).
I would think Cork is too soft and would squash too much.