Break Test Extravaganza(s)

[k7cej]

I have made up two using AmSteel-Blue AS-78, 1/4" diameter, using the button knot with the ends tucked back through and buried.
1. I found it much easier to tie the button knot if I marked one side with black sharpie.
2. Boating friends were impressed, but asked a good question: "If you used one to connect genoa sheets to the sail, how secure would it be when the sail was flogging?" Does anyone have real world experience?
3. Has anyone used this to replace a main halyard shackle?