Eric Brand (ten days FAist) was known to use zmacs to protect, and in bolt ladders as the only type he would use. Those can handle low angle falls like ammons 500 feet of slab falls on WOS on 30+ year old zmacs.
The story changes, I believe in a "pull out fall" where it is very steep and the zmacs are rated very low for pullout strength.
We use 5/16ths x 3/4 Stainless Steel carriage bolts for rivets, buzzed down in various ways to deal with the change in hole diameter from dull bits. You pick the one best suited for how many holes you have on your bit. New bit, less threads, old bit, more threads.
Interspersed with 1/4 x 1.25" button heads with Stainless Steel shop made hangers, stamped with all kinds of trademarks.
Brad- You would feel good above one of our rivets, guaranteed
