I read your email to the bcc group with interest. I believe the name "Bristol Channel Cutter" was chosen by the bcc builders for marketing reasons rather than for historical reasons. The original Bristol Channel Cutters were considered the ultimate in seaworthiness and this is the characteristic the builders wanted to associate with their own fiberglass vessel.
The Hess design is more directly descended from the Falmouth Quay Punt which was renowned for speed and manoevreability, The Punts were smaller boats (24 to 36 feet). They raced each other to supply the square riggers. The design of the Falmouth Quay Punt is more suitable for a yacht than the design of a Bristol Channel Cutter (unless you plan to cruise Greenland).
There is interesting material about the Pilots and their boats. I read an autobiography of Surgeon Admiral Muir(?) of the Royal Navy who disguised himself as a labourer in his younger days and worked aboard the pilots for a season. There is a real Pilot Cutter (I forget the name) home ported in the Gorge on Thetis Island in British Columbia if anyone is cruising up that way.Regards