It’s an option, it’s just hidden, as it willingly irreversibly makes the state between devices invalid, so it no longer makes sense. Even if you disable the option, the state would never converge unless you resort to extremes of deleting the database etc.
You should explain what you are trying to do and why you think you need to enable that option.
Android (send-only) to one PC-device (receive-only) (its a quick, but small location)
My computer “autobatches” daily some of the oldest files to a new HHD (Big but slow)
Then i do not want the files from the android to sync to the pc again