Today I spoke with both the local UK (western Michigan) and Doyle sailmakers. Both recommended using bag weight as the best method for measuring/controlling sail cloth. One offered to provide recommended verbiage to use to help protect against hanging unintended weights on the sail. I will report back when they respond.
Also, both suggested the easist way to come up with a bag weight is to simply weigh a couple of sails. Since I have my original dacron main + 3 string mains I will weigh them all and report that as well.

Further, one of the sail makers suggested that if the class were to adopt going to string sails that it also consider changing the rule on the number of battens from 4 to a max of 5. His beleif is that a fifth batten will help to exptend the life of the sail.

Any thoughts on allowing a 5th batten? BTW I have 2 older ones designed with 5 battens and my newest has 4.