If you really want to go down the rabbit-with-carrot hole… it’s a bit hard for me to say how it should work with mirroring, because I can’t get mirroring to work in general, so I haven’t really used it. What I’d mainly like to use it for is this kind of “in progress” or “today” list, which is likely to look something more like this:
I like the auto-sized headings on the left. What I was asking before, that mirrors go by the destination, would mean that “rabbits”, “carrots”, etc., would be H2 on the right. But in this case I wouldn’t really want the headings to look like headings at all, on the right, but like the other items in the to-do list. On the other hand, I can imagine that there might be other situations where I do want mirrored headings to act like real, auto-sized headings, though again it’s kind of hypothetical because I don’t have much experience with it.
Maybe what I want is different settings of auto-size on/off and default style, settable separately for each pane? Or a system where headings go by their parent, rather than their absolute indent level, so that if you indent one under non-heading text, it just looks like non-heading text? I don’t know. At some point, with mirroring, it’s all a bit “through the looking glass”. One pane makes headings larger, and one pane makes them small, and the ones that mother gives you…