Hi Darryl,
As you will know, you can have your sails cut however you like within class rules, in South Africa the spinnaker is adopted as class equipment as of September 2003, and we have only max. luff, leech & foot measurements, so you can build a really full/flat spinnaker, make it smaller than max, etc. You could even do that with the main, I believe in Australia some sailors in the Mozzie & Taipan classes have mainsails cut to suit their weight. While this might give you an ideal setup for one situation, it would make resale difficult here, a spinnaker cut smaller & flatter would limit it`s use for solo sailing, which we don`t do a lot of.
Instead, we are standardising almost everything - all new sails are from the same sailmaker which helps us to negotiate better prices, and ensures equal performance boats, the epoxy boats are so similar in performance to the wooden boats that it makes neither obsolete, allowing more choice. We`re getting boards & blades from the epoxy-boat builder, but you can still build your own.
I think the end result of all this is that we`re much closer to a one-design class than a pure development class, which is good, as stability ensures that a wealthy sailor won`t buy his way to the front. You could build a carbon Mozzie, but it`d have to weigh the same as a wooden one, so why bother ?
Sorry for the long answer, but my point is that similarity breeds similar performance, which is the goal of the F16 class as well as the Mozzie class. If everyone had different sails cut it would start an arms race which can only be supported by classes like the Tornado & A-class. For the rest of us, it`s not sustainable.