By letting the code formatter exceed the limit if it allows for more readable formatting in certain cases. Going for a 100% hard limit means sometimes it'll shuffle chunks of code around because of 1-2 characters and that just doesn't make a lot of sense.

Or in other words, by formatting the code more like a human than dumping the source tree with a blind set of rules. If Copilot is possible then so is an AI model able to consider how code actually looks on the screen.