So sailor X has a sail made from material not on the approved list because the loft they have chosen considers the approved materials list a guideline rather than a rule. Sailor Y used a different loft that will only build sails from the approved list because... well... they want to build class legal sails and they assume all lofts play by the rules. So not "everybody" has access to the unapproved material for their sails. Those sail makers that play by the rules are punished for doing the right thing and those that skirt the rules are rewarded. Is that really how we want to see the rules enforced?

Again, what is the big urgency to use materials NOT on the approved list? In my opinion it does the class more harm to be lenient than strict.