I can pretty much tell you that creating a separate set of rules for one type of race versus another is a quick way to kill the class. I know for a fact that I'm not going to want to buy two sets of sails for the same boat.

IMO fixing and updating the current sailplan over time is probably the best idea. Next year, the spin gets updated. 2 years later, the main, 2 years later, the jib. This way it gives everyone in the class who would normally replace their sails every X number of years the opportunity to plan when they move to the next cut.