Any conclusions yet about which sailcloth?

I'd avoid add-on tapes such as CF tapes, no matter what the sailmaker promises about longevity. CF tapes are brittle and the adhesive stripes tend to have adhesion issues here and there, particularly where they fold. It can be maintained and they've never separated completely but it's a maintenance issue here and there now and then. If you use tape drive sails I'd recommend fibers that are bonded inside the layers of Mylar/Dacron.

Also I'd recommend a dark colored Mylar/Dacron that has UV protection for the internal fiber scrim. Forget about white dacron trim; ask for grey. I asked for grey and they did white. When I objected they claimed it's not an issue for "just the trim". That was total BS. I let it slide at the time but I regret it. White eventually shows mildew and air pollution stains that never come out in cleaning. White is also more vulnerable to UV damage than dark colors.