Never broke a shoelace (Mk2 and 3), I broke some zipties though. The included ones all broke. The first ones I found in my garage all broke, but to be fair they were at least as old as 1992. I tried some new, smaller ones, singularly and in pairs, broke them. Tried some beefy as shit ones, broke some of them. If I made real sure to avoid having any being above flush with the guard itself, they were fine
Laces are the way to go for several reasons I won't go into, but I used zipties for one side of both my wheels (due to having 4 of them) because it was proving too annoying to thread and dial the laces in like you can with one 1 gland per wheel
Never had a HTP Private Part/clone snag on me back in the day