5% is probably about right around the cans, but how can you get those sort of gains, yes A Class masts and sails will help, but we have to get more drive down lower so that RM isn't the major factor. Allowing the use of a small jib is probably the only way that can be done and no, in my opinion widening the boat, will only create further problems.
It seems to me that making the jib smaller would solve the problem. It wouldn't affect the 1-Up boats at all (because they can't use the jib,) and it would slow down the 2-Up boats. The whole point of the jib in the class, as I see it, is to give a 2-up boat enough extra thrust to counter the extra weight. So if the jib is adding too much extra thrust, then reduce its size.
