This is a great extension, thanks for your work on it. One feature I'd like to see is the ability to make a reply private. Example:
User A starts a new discussion.
-User B replies to the discussion
-- User C leaves a private reply to User B's reply
This could be used when you want to reply and only want a select group of users to see your reply (maybe you're posting something personal and want it limited to people you trust without. But, you don't want to start an entirely new discussion, as your reply fits into the current discussion).
I can see this being a potential problem as users could use it to mock others. But, I think the ability to make private replies to any discussion on the forum opens up a lot of possibilities for users to share more and become more engaged, where they otherwise might not open up as much.
Another feature that would be nice is the ability to create your own groups. Something like Friends or Foes on older forums. I'd like to create a group of people I may know in real life who I trust to see my private posts, or maybe a group of people who are interested in certain topics where we can have private replies/discussions within a public discussion.
I apologize if this has been mentioned. I didn't see it while reading this discussion and it doesn't appear to work based on my trials with the extension in a freeflarum site.