Anon wondered about SEC_TEST. >>179561
My 2c:
Board was under heavy DDoS attack at that time.
Q needed to test how long a post takes from when he hits enter until it registers on the board, in order to deliver accurate messages via the time-stamp.
The delta from a past POTUS tweet to a Q post on the board serves as an index to look up a past Q post. (But I don't know quite how this works).