Old IS Blue Lake.... anybody tried different future fins?

So the old IS boards use future fins, not the newer IS proprietary fins. I had a mishap in the storage unit with my blue lake and broke one of the future fins (don't ask!). So now I need to replace. I've ready about people going with longer fins for more drive and I'm wondering whether anyone has tried any different sized future fins in one of the older boards?

Presumably the same question would apply to Yellow Loogie riders out there.

Were they Future's or the O'Fish'L fin boxes? Futures has the 2mm set screw in the front and the O'Fish'L box just had the little plastic clip, no "tools" required to remove the fins. We had whatever the red board was back in the day and we swapped some fins around, it was fun if not really productive. We wound up going back to the original fins. YMMV.