Call me “old school”, but I’m still a fan of the bowline. I can tie it easily and quickly. I have never had one come undone or fail. And, when properly tied, I don’t have a problem with the knot hanging up on the forward shrouds (make sure that the loop and tail aren’t too large and the tail finishes inside, not outside of the loop).
If your sheet is properly sized and made of the correct material, any knot you tie should not weaken the line to the point of failure. Your sheet will be stretching and ruining your sail shape long before any potential breaks. If you are still worried about this, stop buying clothesline from home depot for your sheets!
I am probably a different than most sailors as my gear is more performance oriented. I run spectra genoa sheets and they are too expensive to leave them out, gathering (salt and grime) between sailing weekends. I take them off and put up a sacrificial line for my furled headsail. I have different colored whippings on each end so it is easy to constantly swap them end for end. I don’t get much wear from the knots, but I do get a lot of cover wear from my winches so swapping is a good idea for me.
When racing, we do peels and cruising bald headed changes while underway. Either way, I want to use the existing sheets rather than string new ones with each sail change. Also, on light air days with long runs or deep reaches, we will untie the lazy sheet entirely to get the weight off the clew. We will even swap out to our “dental floss” if conditions persist, so a simple, quick, reliable knot is important to us.
I have used the Tylaska J shackle and although light and compact, I have had difficulties in getting the pin out while wearing gloves. I have no experience with spool shackles, and I wonder how well they will hold up to a flogging headsail. They do look intriguing however.