thanks, appreciate it.
I actually have a hypothesis, perhaps you can confirm/deny it. In the shortened form, the text field contains a link to the expanded URL. in the extended format of the same tweet, that link is nowhere to be found because it is, by definition, the extended format of the tweet.
to give you some more context - we are trying to create a method to convert from extended format to compatability+extended format - see this for more background. based on the above, it seems that there is no way to definitively replicate the same truncation process Twitter is doing on their end, right?