Continuing the discussion from Wow! And a few requests and questions already:
Here’s how Discourse envisioned a conversation branching. You can reply as a new topic (there’s a link to the right of each post). Now, both this topic and the one that it came from reference each other, and you can read both.
Since there wasn’t a tree view discussion outright, I created one based on the original thread.
I realize that branching topics requires thinking about it, and that not everyone will do this at first, but I find it a pretty reasonable (and preferred) way to go off topic.