I don't see myself using rules, since I can do almost the same thing with headers, which are more SEO friendly and work better for blind people and screen readers. A line rule is nothing for such kind of software and, in my opinion, shouldn't be used at all.
Besides, I don't think a header would give excessive emphasis, since it just
separates contexts inside an answer.
Less critical content supports the conclusion and doesn't need to be separate in such a drastic way. Instead, you can bold or empathize the parts of the text you really think are important. That would clearly make sure the reader gets what you want.
So, like I said, rules exist and there's no point in ruling that they should not be used but, in the same way, I don't think they should be advised what would inevitable happen in case we create best practices rules.
Just leave them be. If somebody really thinks it's necessary to use rules, ok. In general, we can just try not to use them.