'In my opinion a well sailed "stock J/30" will still be as fast or faster than a "tweaked" average boat.'
I don't really mean to start a debate, but I'm not sure how you reconcile that statement with allowing unlimited materials in the main especially? A kevlar main for a J/30 is rather pricey, and from the sailmakers I've talked with, not a big gain.
I hope the class will continue to keep the cost of racing my boat reasonable.