Even when you think you thought of everything ahead of time, missing something is inevitable. Case in point, I didn't consider that I would want to control the stepper motor being energized or not. The use case is that there is no reason to keep the stepper energized when the carousel is not spinning and when the doors are all closed. But it is useful to energize if you want to 'lock' the carousel in place to prevent people from pushing the sides while a door is open.
The prototype PCB didn't have this pin connected, so what to do? Jumper wire!
The eagle file has had this connection added in, so future runs of the PCB will not need the jumper.
Just an example of how to deal with change on the fly! :)