RE: use of weed fins on evo and acid
I never use weed fins, so I can't really comment on that issue. Neither did I try what happens if you move a normal fin all they way back to try to emulate the weed fin feel. Generally your board gets a bit more directional when you move the fin back, but if I go too far back on an EVO, I don't think I get the balance I want, so I never do that.
Your "reverse mounting" trick sounds like it must help.
The expert on weed type wave fins must be Wardog who post here sometimes. You might try to page him at the Hot Sails Maui forum too (haven't seen him here for a while, as far as I can remember).