With all due respect, I disagree with what you're saying here.

"It's a bit misleading to use the stdlib as a guideline"
... when looking at the style guide for the stdlib? I appreciate that PEP 8 is used for other purposes, but its main purpose is clear from its very first line.

"There are reasons we do this in certain spots"
Yes, there are. And given that there are so many of these different spots where it would give better performance to ignore the rule, PEP 8 should reflect that.