OK , this is what I have learnt about sails recently being a heavyweight.
Go big , huuuuge down haul .
Take a big gulp of downwind to get going because the sail feels weak.
Once going it feels good and were fast even with a big board and fin.
When a big gust hits , it's painfull , but that's as good as it gets so get used to it. Racer guys think this is normal so stop being a whimp.
Or get off the good life and be 90kg .
Im 120. and I'll wrestle the gusts