It sounds like when you say "requirement" and that you "can't share code" and the result would be "unacceptable", you mean something else. Something like, "I just don't want it like this (even though there's not actually any hard and practical requirement here that it does the thing I want)".
> even though there's not actually any hard and practical requirement here that it does the thing I want
The practical requirement is the user interface.
The entire purpose of the <hr> in <select> is to visually separate the options for the user. If the visual separator only appears for some users but not for other users, that's a failure of the user interface.
Imagine if it wasn't Mac vs. iOS users but rather that there was a WebKit bug where the <hr> only appeared 50% of the time, randomly, for Mac users. Wouldn't you consider that to be a problem?
It feels like you just deliberately want to misunderstand me. What exactly do you think "requirement" means, and where do you think requirements come from? Only from God? Only from laws of nature?
