User inbox as a comment system?

I’ve been thinking about this for a while. Is it possible to leverage the activitypub inbox/outbox as a means of basic interaction? For example:

  • If someone replies to a post, display the type of interaction and a link to the original post below.
  • Show only the last n replies.
  • Blog owner can block/hide replies.

For the sake of simplicity, the blog owner would not be able to reply to themselves, or another post on the site. I imagine that will be a another big project.