Would it be acceptable to use the RegWrite function in generalutils.brs to save the serial number of the device to the roku registry for the channel after it has been successfully linked, and read it back from the registry with regread to send to the authentication server if it exists when the channel loads? That way it can still be checked to see if it's there, indicating the device has been linked, it could also be cleared with a factory reset, and if it doesn't exist then go through the link to new account process as normal? Technically that wouldn't be sending the serial number of the device for authentication, but a copy of the serial number for the device.