To make a larger sized retro twin turn easier would it work to add one set of wings?
Either that, two sets of wings, or add template curve centered max right at the leading edge fin placement.
If the board is already finished, you can narrow the chord on the fins for quicker turns.
Of course, if you are building the board, then more toe-in, some cant, forwards placement of the fins, or increased rocker right at the fins would loosen the board and make it turn easier.
It would work,but then it would not be a “retro” twin fish. Peace and waves…
Sean W.
I had a few Lis fishes with wings in the seventies. I had one grey one with a yellow arrow that I got flawless hollow offshore, uncrowded malibu . So retro shmetro! here is a recent Pavel -double bump, wing fish that my friend has ridden in heavy double overhead reefbreak and said it went soooooooo fast!!