I created a new screen for bugs. Within in this new screen, I reused some of the fields on the previous screen. When I saved the new screen and enabled it for the Create transition, those users who had their create screen set to Configure Fields - Custom, did not reset.
What this caused was important fields being hidden, the context of tabs that was now present wasn't honored, etc.
How does one force all users to default back to 'All' on Configure Fields when a new screen is defined?
It seems best practice for this to happen automatically, but obviously it's not.