There's an area in our gym that is only covered by 3/4" rubber matting. Dude cracked the floor underneath only deadlifting 315 with iron plates. Bumpers are okay though.
Pretty dumb because we have deadlift platforms with a couple layers of plywood and then the horse stall mats on top of them.
A certain well known powerlifter I know (who squats a lot more than kstar) injured his hip pretty badly early last year messing around with a "toes straight" stance. Paraphrasing, but "always open to making form tweaks, but that one? never again"