The idea isn't bad and I think it can be pushed deeper, motivate the author to interact in the process by replacing the part where it's you who take the link of the comment to put it in the POSH Curation compilation posts by:
The author answers the @poshtoken comment in the form of "Thanks @acidyo for your tweet...."
Ok, it will take a little more time to put in place because it needs dev to retrieve the answer to @poshtoken comments but it's not really hard and it can create more interaction on the post itself.
I also think you should keep the old system for authors who include photos or a short video in their tweets (which reaches more people) because only they can do that.