Recent service changes to 31xx movements??

[Dirt]

I understand there are occassional changes or updates to service parts.
My question relates to my recently serviced 116660 which is absolutely sublime to wind and set. It was great the last time it was serviced in 2017 and better than it was from new, but it's superb now

More specifically my question relates to when i came to set the time, there was no appreciable springy backlash of the Minute hand when turning the hands backward which made setting the time easier than it's ever been.

Does anyone with more intimate knowledge around this have any insight they may care to share as to why this may be so?
Have there been any updated parts for the 3135 which would contribute to the reduced springy backlash?

Many thanks