I've used a bowline for halyard attachment to sails for decades. Hate shackles cause they will beat the s**t out of you if they get loose and they will. The tail of the splice necessary for a shackle can jam in the mast head sheave if you hoist the sail to the max. The bowlines have been up for a 24 day and several lesser double digit passages without an issue on the halyards or sheets. The big problem with bowlines on sheets is they can shake loose if you don't leave a generous tail. The buntline hitch and the blood knot may not have that problem as they lock the bitter end in as they are tensioned. Have not had a problem untieing either the bowline or buntline hitch even after many days in use.

Because of that, went with a buntline hitch on the main for the sail to Hawaii. It worked fine. Used a brummel splice for the furling genoa. Great solution to the hassle of sheets hanging up on the lower shrouds. The disadvantage of the brummel splice is ithe sheet is dedicated to the sail but not really an issue with a furling jib that pretty much gets put up and never comes down in normal use.