Thanks for the info... I know my Ultradive definitely does not have this feature however I am curious if any other movements had this feature added later on.
I am unsure about the history of the hacking seconds feature. I know my 62GS Grand Seiko from 1967 even has this feature but I am pretty sure this was pretty special feature in the 1960's...
It might also interest most that most Patek Philippe watches don't have hacking seconds feature even today.
I don't believe Rolex watches had this feature added until the mid-70's...
On my watches which house either the Valjoux 72 or Excelsior Park 4/40 movements I wait for the watch to wind down to where it will need rewinding soon. Then I pull out the stem and apply a little bit of back pressure to stop the movement until I'm ready to synchronize.
From all the reading I have done, it is safe to do so, so long as you never allow the movement to run backward even for a couple seconds.
I have been doing this for years with no ill effects.