G'Day Van Isl,
of a large genoa
on a furler
sounds good when you say it fast, but reality suggests that there are problems with the approach. In order for the gennie to be a good light air sail it must be built from fairly light cloth. Then when the wind
pipes up, you roll a few turns to reduce sail area. With a well designed foam luff pad the shape isn't compromised too much... until the too light cloth begins to stretch. Then the shape goes to hell pretty quickly and heel angles increase again, so you roll some more turns in and the process repeats. Not only does the sail perform poorly under these conditions, but pretty soon the un-reefed shape is all stretched out and performs poorly even in light conditions.
A chat with your sailmaker
will help resolve the best compromise for your particular boat and cruising area. My guess is also in the area of 120% and medium weight premium Dacron cloth. A tri-radial design may help extend the range and lifetime of the sail albeit at a higher price
... we've found that to be a useful expenditure for our useage.