Rinse would have to add the post number value to the backend, an index counting the comment in the subplebbit database. Then Esteban would have to add a hook to his plebbit-react-hooks repo that would allow plebchan to convert the post number value of a post to its CID, so it can be used in the post URL, and plebchan users would be able to create URLs with post numbers, redirecting to the correct URL with the CID. Then I'd implement the post number API and the hook in the frontend, to finally make plebchan look identical to 4chan.