Sorry for the confusion about the RSS feed. Pretty much we have an RSS feed that is crawled every 5 minutes by Discourse to create topics for entries on our site. This creates the topics on our Discourse with the appropriate title and description. However, if someone were to visit the page for that entry after the entry was added but before our RSS feed was crawled again, then Discourse would automatically generate a topic and then display it. This would normally be fine, but in our case this will not generate a topic with the correct title, so we would like the Discourse topic to only show existing topics and not create one if it does not exist for the current entry. From my searching this seems to only be possible if you reference the topicID of a topic.
I do like the idea of only creating a thread if a user decides to create one, as this would keep our Discourse site less cluttered.
It seems that for my use case, it might be easier to fix the issue I mentioned above on my side (title not generating properly).
Thanks for the response. Cheers!