Wolfgang himself may chime in here with some info.
I've worked with him a bit on modifying his designs to set the fin
further forward, but like all the "fin making magicians" he does not
like the overhang because it can cause problems with getting a tight
fit/seal between the overhang and the bottom of the board just in
front of the fin box.
Most sailors do not want to "fit their fins" and unless you use a thick
rubber gasket (a different set of problems) under the overhang, there
is the chance that weeds will get between the overhang and the bottom
of the board and become trapped, so they then cause the same problems
the weed fin is supposed to prevent.
Wolfgang's asymetrical fins do not seem to have the same "rudder effect"
that you find with other high rake angle, not set forward, weed fins.
Give them a try, they are fast, don't change the feel of the board too much,
and shed weeds really well.
You have to get one of Wolfgang's beautiful fins in your hands, and rub/touch
the asymetrical foil to really appreciate his "artistry".
Hope this helps,