I see the value in extracts as an indicator that watch is to factory specifications. That is, it has a movement that matches the case style (As evidenced by serial number and case number)
I remember quite some time ago in the Jean-Luc Miranda period that one had to send photographs and other pertinent information so as to fully establish factory specs. Remembering that case backs are interchangeable on a number of models within a series, with the current service there is no guarantee that the actual case is consistent with the movement because they do not use pictures to verify.
I've communicated with people during those days who were refused a certificate on the basis that the pics didnt show the correct case body.
So, it's a pity that the service is so limited. I would do what Erich does as that at least makes them go search the records. I still find the service useful, particularly with more expensive pieces e.g. was the watch head delivered on leather and accessorised later, and particularly with precious metal welded bracelets where it is important to know if the bracelet was factory fitted or added later)
Cheers
Desmond