Just for conversation only, I am not working with a lot of experience here.

If the dude is looking for good times where he doesn't go out if it isn't blowing 15kts minimum, why not go for the "reefed" version of the sail. A Pinhead even perhaps. As ?PTP? suggested up thread the gybes can be hairy with all that tipping force at the end of the mast.
The beauty of the square top is the twisting off when the power isn't needed. He doesn't need it. Ever. When off the wind, that big ole flap turns broadside to the wind and gives a big push.

This is taking the multi-purpose F16 tool and converting it to a single-purpose (Higher Winds) weapon. If what he wants is light weight and spinnaker equipped, why not purpose build it. A flatter, smaller spin would be in the recipe too.

Just another keyboard sailor thinking aloud. Getting more snow today. <img src="http://www.catsailor.com/forums/images/graemlins/frown.gif" alt="" />