Bumping this one just to say that these mods have been working now for three years, with only two failures. One with the washer/flame style and one with the metal crimp style. The failures both times were where the button allowed the bungee to slip through, no damage to sail material (which is what I definitely wanted to avoid). Both failures occurred while teaching new flyers, with typical new flyers' hard impact on grass. Intermediate-and-up flyers should have no problems, barring any SEVERE impact.
Yeah. I was one of them. About gave me a heart attack one of the first times on the handles.