Hey Christopher! You're welcome to use Branch this way, if you'd like. We haven't built a plugin, but a few people have hacked branch as a discussion tool on their site.
I added a friend of the company Tony here, too, who built this: blog.tonyhschu.ca. He's used branches as point-by-point discussion tools.
More simply, we give you access to a short HTML embed code (just like a YouTube video) in every branch you've started or joined. (Take a look in the upper right-hand corner.) You can just paste this into the HTML field of a post and you can add a few folks in to discuss what you've written above/below it.
Can I answer any questions?