Won't be as clean as non furling
sail on a Strean Stay but won't affect the performance that much if done properly. If you are One Design racing
it would be another story but then you wouldn't have a roller furler
on the boat. The sail will set way better when reefed in heavy winds which is what the foam luff is all about. If you will only be furling
the sail, not reefing it, doing away with the foam luff is an option. To me, would much prefer a better setting sail when reefed than the small, if any, loss of unreefed performance. FWIW, the bulbous roller furling
extrusion is probably more harmful to sail performance.