My reasons for buying Graham's plans, and my use of them, (unless I violate some copyright) are my own and are personal; private unless I choose to share them and not subject to anyone else's assumptions, definitions or declarations. (In actual fact I didn't buy the plans; they were a delightful present from my loving wife but that's irrelevant and equally no one else's business.)
I do hope to hear from folks with details of mods & adaptations they have made; whether those changes achieved the desired result, and what was learned in the process. I'm not so interested in splitting hairs about what amounts, or does not, to a "design change" or interested in what anyone "would never think of doing" unless a) they've actually tried the change and in consequence have decided never to do it again. or (b they can show specific and valid physical reasons for dismissal of the idea.
I have great admiration for Graham and Carla and for his design of the little Spindrift 12 (which I am proud to own) as well as for their helpful advice when I was building it. Please DO NOT - anyone - try to suggest otherwise.