Hi all. What happens when I change out an AS4812 + F controller.

From what I can glean from different posts and the service manual I would replace the controller (not sure if I can use any of the three types in any position - 1FU, 2FU or 1.1FU).

Is the 1FU etc. defined by internal programming or do they all run the same firmware and are differenciated by the parameters that I would set. I image they know which physical role each one takes by the canbus connector?

I'm pretty sure I need to change an eeprom on one of the controllers so I'm trying to get a clear idea of how it works before I begin surgery ! Thanks in advance for any light anyone can shed on this.