In-reply-to » @tkanos a quick question, I'm using twet (thanks for the recommendation), how do the clients announce between them that you have replied to a previous twt? If I remember correctly, we were discussing a few months ago options like Webmention, I have never used it, although sounds better in my mind than parsing the access_log.

That search engine you mention or a global Database of Twt hashes could help. I remember that Twitter users had an external search platform, acquired later by Twitter:

As said, a comment in the txt file like: Notify me on this email, or automatically register your feed in this URL as Antenna does, would be a nice addition.
I assume that if you are replying you are interested in making a dual connection, so they can answer you back. Just thinking out loud.