RE: use of weed fins on evo and acid
While I can't comment specifically about Evos and what works and doesn't with them in particular, I can say that there is an older True Ames wave fin that does quite well in the weeds and kelp without the normal 40-45 degree rake associated with classic weedfins. The great thing about the fin is that it has a remarkably shallow ramp (quite viable in a US Box), yet still has a narrow chord because of the notch at the base of the fin. The fin is a special order fin called the "Wave Ramp", and it's manufactured in G10 material, so its quite tough but very precise in shape and flex, and it's clearly a wave design. This is the fin that I normally use for waves in really tough kelp beds, and its remarkable how well it sheds weeds and kelp, yet its still quite loose and maneuverable in nature.
Although other newer designs exhibiting a longer lower aspect keel-type base are certainly available, I wouldn't discount this older concept, as the ramp is very minimal in nature and it might better suit your idea of the right design concept. Unquestionably, its a personal call.