I need to use multiple Android user profiles* sharing the same physical device, without Google (or any other party) knowing that the device is shared--essentially to make Google think that the accounts are completely independent from each other, and not connected in any way.
Per my earlier question, Google is able to cross-match user profiles (accounts used to sign in) based on equal IPv6 address.
Now, if for each user profile I set up a separate VPN service, each with its own provider and VPN user account, and enable "Block connections without VPN" for each of them, will that prevent Google from cross-matching those user profiles by IPv6? Looks like I will need to temporarily enable Airplane mode for every profile switch, and for every system reboot.
[*] As managed in Settings > System > Multiple Users as of Android 11; not to be confused with Settings > Accounts.