I decided to reg my Mini 2, got to the part where they ask for a serial number. Not sure which one to enter. Aircraft or Flight Controller? Watched Pilot Institute on YouTube, they said flight controller then late said aircraft, didn't mention the Mini. My app shows this:
Battery SN
Aircraft SN
Flight Controller SN
Remote Controller SN
Camera SN
Battery SN
Aircraft SN
Flight Controller SN
Remote Controller SN
Camera SN