I started discourse this month, and although the option is very good, I have found the same problem that you mention.
In my case, when creating a topic, and writing the watched word several times, it changes everywhere (even in H1 titles), so I have a “spam nest” in all the source topics.
I would at least like there to be a code to put in the paragraphs, where I do not want the aforementioned rule to apply.
I don’t know if, due to the time that has passed, you have already solved it in some way.