Custom fields for followers

I am trying to fully understand the logic behind Custom Fields in Intervals.icu. I train athletes and currently have the Custom Fields set to full access, which allows me to add them to my athletes’ profiles. That part works fine.

My question is: What happens if I update or change the script on my end? Does it automatically update for my athletes as well? Is the Custom Field variable only imported once as a static copy? And if an athlete makes a change on their end, is that synced back to me, or do they keep their own local changes? In short, how does synchronization behave in this context?

If someone uses a Custom Field, they make a local copy of the field as it is at that moment. Changes on either side are not replicated.