We want to send folk from our Blog to our Forum as most of our moderation occurs there (the forum). We do not, however, want to force people to the forum just to leave a comment, so the idea is to have a limit on Wordpress comments (let’s say a max of 5 comments) before a “Continue the discussion on Discourse” message is shown. That way, if a topic is getting quite a lot of interaction, we would rather move that conversation over to the Forum otherwise we’re moderating both the Blog and the Forum.
Is it possible to show a link to the forum topic after a certain number of WP Comments have been created?
I don’t recommend it. Your conversations will be in two places, so all it demonstrates a false sense of social proof. Better to funnel folks into Discourse.