I've been maintaining a browser extension[1] that has used various versions of the unofficial API over a period of six years -- from literally navigating the site as the user and grabbing HTML, to the various incarnations of JSON and HTML hybrid (SSR) APIs that their web and mobile clients have used internally over that time.

Believe me, I would LOVE if the official API supported threads. I have tried several times to make it work, but the official APIs are stuck in a circa-2012 idea of how Twitter works. Replies just aren't a thing to it.

[1] https://github.com/paulgb/Treeverse