i've broken a clip before as well as two straps (both nylon) and worn out even more.
i now ride soma oppy 4x gate clips with two straps each. i don't like that i'm riding leather, but i hide behind the fact that i bought them a few years ago, before i was vegan.
the straps are leather/vinyl/leather, and are remarkably strong. i've been using them for a month or so now, no signs of stretching whatsoever.
i now recommend double setups whenever i'm asked, mainly because i've realized that no one's really designed anything specifically for the type of riding we do. yanking up on toe clips over and over and over and over is more than they/the straps are designed to deal with, so we go through them pretty quickly.
soma's clips are the closest i've found to a real solution, and riding them with beefy straps is probably a good idea.