Picture Lock: Why it breaks, and how to survive it?

Hey everyone, as an AD, I've seen 'do not break picture lock' written in practically every post-production guide out there. It’s presented as this cardinal sin, and I get why, ripple effects, wasted effort, etc. But honestly, I've been on a few projects where it happens anyway. We were cutting something for a client with an ALEXA Mini, then later a commercial with an AMIRA, and in both cases, changes inevitably came down after the 'lock.'

What are the actual, real-world pressures that force teams to break picture lock, even when everyone knows the risks? I'm talking about the unavoidable stuff that blows past even the most iron-clad schedules. And more importantly, when it does happen, what’s the best way to mitigate the damage? Are there specific communication strategies, file management tricks, or anything else you’ve found effective that doesn’t just involve sighing into your MKH 416?