Add an post option that allows sub mods to lock or unlock comments on that post. When a post is locked to commenting, replace the comment reply box with a notice that comments are closed, remove the reply link from the post's comments, as well as from the user comment list and from notifications, and refuse to create any new comments at the comment creation endpoints.
While I was at it I also removed the reply link from archived posts when those show up in a user's comment list or notifications.
Add an post option that allows sub mods to lock or unlock comments on that post. When a post is locked to commenting, replace the comment reply box with a notice that comments are closed, remove the reply link from the post's comments, as well as from the user comment list and from notifications, and refuse to create any new comments at the comment creation endpoints.
While I was at it I also removed the reply link from archived posts when those show up in a user's comment list or notifications.