I know a guy who was stuck as an FO for several years when he didn’t upgrade before 9/11...could have held it, but once vacancies dried up, he was about 10 numbers away for several years because everyone took it ASAP from that point out.... 30 numbers could cost you hundreds of thousands of dollars over your career worst case, or it could be negligible, but there is always someone who misses something by just 1 number....is it worth it?