Either take the name from the AFTV e.g. I have mine named AFTV-01, AFTV-02, AFTV-03 or add a menu option in Plex to allow us to manually name the Plex Client.
I think this has been requested multiple times, and considering there are more than enough people with multiple AFTV devices I don't understand why this is not already an option!
thanks
Alex