Actually #3 I have seen cracked, which can make the boot get pinched or let crap build up inside the boot.

Sent from my SM-A730F using Tapatalk

__________________
"When the Team Chief said.... You're trapped in a hole with nothing but a goat and a slinky, what do you do? Stubby said, I'm not sure but it won't end well for the goat...." ~(Overheard) Last day, Phase 3, Q Course