rob006 these are two separate things. Using nofollow
has been a recommendation by Google itself which was introduced to combat deliberate schemes for improving page ranking, see this: https://developers.google.com/search/blog/2019/09/evolving-nofollow-new-ways-to-identify
It concerns user generated content which is what a forum is about: posts with user generated content.
Now, internal links should usually not be marked as nofollow
but, and that's the important thing, the reason is to allow for better indexation of the websites, so that the crawler can follow the internal cross-links and crawl through the entire website. But, this is valid only for regular websites where you have a bunch of pages, some of which may not be otherwise known to Google unless linked to from other pages on the same website. And this is not what a forum is. A forum has threads/discussions with posts. All that is visible to the crawler. All posts are available and accessible and you don't need to post links to one post from another post.
There's just a lot of misunderstanding and people just follow (no pun intended) blindly some generic recommendation about SEO they read on the Internet, without actually realizing what's the real meaning behind that. I stand behind these words. Can you tell me why you would need to have cross-post and cross-discussion links to your Flarum to improve its SEO? I never had answer to that question. Nor I have seen Google recommending that you provide such links for a forum to improve its ranking, nor its indexation. As I said, you have the sitemap provided to Google and it already sees all your discussions and posts, that's about it. Linking to particular posts from other posts is a dubious advantage.
But anyway, there's an extension which @luceos prepared, that's pretty nice of him, so problem solved, all people are happy š What I wanted to clarify is why that is important because by reading this discussion I thought something was wrong with Flarum and my forum won't get indexed correctly, or will get ranked really low due to a faulty link handling. Which is not the case, and I doubt you would disagree.