I would recommend avoiding the twin jacketed lines that are promoted for this purpose. It is really difficult to get the outer jacket to stay in place. I tried several time with different makes and stitching ideas. I finally gave up and returned to normal setup.

For me, tapered caused higher friction at exactly the wrong moment-- when I was transitioning from in tight to out loose (mark rounding or quick dump of power to avoid capsize). The added friction of the taper point occurs just as the force of the mainsheet becomes weaker.

he benefit of low drag when in tight trimming is nicer, but just not worth the trade offs for me. The trade off was even worse when there was any defect in the transition point. Finally, any defect at this point would cause bunching which would increase the defect until I had to stop the boat, cut the line, re-thread, and continue racing. ... no, definitely did not work for me.... If you try, for sure have a pro make you one. Annapolis Performance Sailing is very good at splices if you are bound and determined.

Matt