> Completely ignoring the other phrases I quoted, which (taken at face value) contradict your reading.

You are taking them out of context (literally this is what you describe here, taking at face value a smaller quote).

I think your approach to interpreting the spec is not correct. This isn't code, it's a spec: it needs to be read in full context (even though a good spec would certainly be written in a less context-sensitive way, this is not a perfect spec -- have you ever seen one?). You're not a computer or a machine, you need to read it more like a human, even though we're all trained on the concrete mechanics of computer programming. Yes, even though it's describing a programming language, believe it or not. All specs have flaws and need nuance in those situations or you will either (for language specs) write code that doesn't work anywhere, or you will write a compiler that breaks code matching what the authors of the spec intended to allow.

> Right now it looks like you have an impression of UB that doesn't match reality.

I have an impression of UB that is not the convention, my post is criticising the convention. I am trying to give context and nuance where it is unfortunately lacking and now apparently quite relevant to lots of people. This can't change reality of current compilers, but maybe it can serve as a lesson in history.