Remember how PHRF works. Again, P is for performance. Data is required to change handicaps. In the case of a change in sailcloth weight, a rating change will not happen unless race data justifies it, since no dimensions were changed. However, if race data shows that spinnaker cloth weight did change a boats performance, a committee will either change the rating of the boat that is using the illegal sail, or will change the ODR rating if the class adds the light chute. In my earlier example, would I win the protest? Maybe not, but the committee would hopefully start to track the performance of the boat using the light spinnaker, and bring it up at a future committee review. There is precedence here. Take a look at the rating credits / hits that some fleets are giving for sail cloth for headsails. In the Melbourne fleet, a Dacron only inventory is worth 6 seconds per mile. Even the IMS rating includes sail cloth credits. So, in theory, I could enter the PHRF championship with my J-30 ODR rating, use brand new Dacron sails, and everybody would have to give me 6 seconds per mile. Again I say choose the sails that make the boat most enjoyable, and forget about the ratings. Suggest all interested have a look at
http://www.ussailing.org/racing/offshore-big-boats/phrf/