@Reason: I guess it's a language issue with the manual then as it refers to "each device" when they probably meant "each control surface". And...wouldn't it have been more flexible to assign overrides of the control information at the Reason device level? Each device has to have its own mapping anyway.
@RXTX: "Override" doesn't imply contextual scope. As you have helped me understand, the overrides here are global for a control surface in the context of a song. Thanks for that