Background: At Wikimedia, we've designed an IRC bot that polls feed.query and uses maniphest.gettasktransactions to get more detailed information about what happened in each event. There's currently no way to get information about individual task transactions (I believe that's covered by T5873), so in the meantime we've been comparing the timestamp of the feed.query event to the transactions from maniphest.gettasktransactions (code). This worked well for a while, but I soon discovered that while 70% of the time that's the case, there are plenty of times when the timestamps are different.
So, would it be possible to expose the transaction phid (in the form of PHID-XACT-TASK-something) in the maniphest.gettasktransactions output? Since those are provided by feed.query, that would let us properly match them instead of relying on fragile timestamps.