So, in effect, you are shouldering the burden of R&D costs yourself:
- you're paying for the sail with its new configuration
- you are sailing it and judging your performance change
- if it turns out to be a dog, you wasted your dollars on that sail, and will have to buy another one
- if it's a clear winner, the loft will sell the "new" design to other sailors

I guess if we're constraining our sailplan change to only sail shapes, perhaps this open development is feasable. What if the class considers an entirely different sailplan that incorporates a wing mast?

In my opinion, I think that something major like that should be undertaken by the factory (since their name's on the back) and I would be more likely to pay more for equipment to offset their R&D costs which would presumably be much higher.

For instance, with a new mast, would you want to change shroud/forestay measurements/angles? Would you need to reshape the leading sails to optimize the wing mast? Would a different boom/rotator configuration be more effective? How about mainsheet system? Would there be any changes to the mainbeam to accommodate these other changes? All those answers cost R&D money... likely far in excess of just trying out a new sail or two...