What configuration settings control who gets the notifications of additional payments? It seems like it just sends a notification to the same people who are set up to receive registration notifications, but I don't want that to be the case. Can this be changed?
There is no configuration for that. You are correct... the email(s) that are set to be notified of registrations also receive the notifications for any activity made in the user panel.
It would be helpful to have a separate control for this. The organizer of our event wants to be notified of new registrations, but not all of the payments. Since we allow partial payments and have periodic payment deadlines, the amount of emails we all receive regarding these payments gets to be a lot to deal with.