Is the mechanical watch certified by Swiss Observatory more accurate than that without certification?

Observatory certification refers to Swiss Observatory certification, namely C.O.S.C (Swiss official astronomical clock control). Test centers in Geneva, Bill and La Saud, Switzerland. Used for exercise testing, not tabulation. It must be a single exercise test certification, not a batch exercise test certification. Fourthly, it is emphasized that the detected movement must be equipped with a second hand, and it must be able to continuously monitor the progress of the second hand. Watches sent to the testing center will be tested for 16 days, including five-way tests at different temperatures. Only those who pass the test can get the certificate of the Observatory. The error standard is -4/+6 seconds.

If there is no movement certified by the Observatory, the normal travel time error of the mechanical watch is +-30 seconds/day.