Andrew,
Wouldn't a sail cut for a flexible mast (needing bend to flatten) be too full on a stiff mast, rather than too flat? Agree on the non-competitive assessment.
Sander is considering putting sails made for a Tiger (stiff mast) on to a Nacra (flexible mast), exactly the opposite of what you describe. In effect, your statement is beside the point, irrespectibally of the fact that is it in itself a true statement.
Wouter
