I have seen a norm in Discourse forums that topics get into a meta or tangential discussion far too easily and then the original topic somewhat dies. This happens more often on some forums than others, but I suspect the majority of Discourse users do not know that reply-as-linked-topic exists.
If the option were exposed when replying (instead of requiring a click on the reply-arrow icon), it would get used far more often. It would prompt people to consider it (which I’m suggesting would be great).
Perhaps radio buttons, maybe two or three of the options are exposed with a “more” link to show others.
At the least, it could be made an option to have it unexposed.
I suspect this would have a huge improvement in the nuanced choices people make about how to engage most effectively.