One solution is create a new Nacra 20 level rated class.
It would include:
Stock boats approved by Performance
Stock boats with new sticks and sails approved by Performance
Modified N20's with custom sails that measure into the stock sail plan.

Get a new guesstimate from Portsmouth/PHRF for the new class and carry on. The Nacra 6.0's did this with the listing of the N6.0 with the NE chute.

For each event on the schedule... let the registered boats politic with each other as to what the class will be. You assume that everyone wants the largest possible class to race with wand will sort it out prior to the starts. Back in the day, the hobie sailors would get a new sail and then send it off for a recut to get what they wanted. The racers let this slide because it made for better racing. I personally never saw a protest over.... Your sail was recut...blah... DSQ!

Forget about class sponsored development... the rest of the world shops for a sailmaker that will deliver fast sails and good customer service individually. Your sort through the hype and BS from each sailmaker and buy what you want. When you get the sail and mast to match your crew weight and sailing style... You are VERY VERY HAPPY. Its a fun part of the game.

We got a new North #1 for the J35.. Put it up for the first time and it sucked... Lots of experience on the boat and we pulled every string combination we could think of...sucked... put the old one back on the next day and we were back up into 3rd... a month later the sailmaker came out.... Tweaks that we did not make later.... the sail looks perfect and is fast. My point.... service is an essential factor in what you purchase!

You are buying a sail design, cloth, construction quality and a service. It's part of the game.

Just organize the game to be fair ... label the class properly and move on.

Rick White did not emphasize this key point... the slang is to speak of the "WAVE" class but in fact... they have a distinct class name from the HCA Wave class. It is in fact a level rated class that includes the stock wave.

(We would never have known that the GT300 N20 class was actually a level rated N20 class prior to your post)