The Privacy plugin is designed to work best with client-side cookies.
The use of server-side cookies is therefore not recommended. This is because of the necessary synchronization between our cookies, and the need to know the privacy status of a visitor in order to apply the treatments correctly. In the case of client-side cookies, the JS has direct access to the cookies and can therefore process the visitor ID (idclient) according to it (opt-out for example). If the visitor id cookie is server-side, the JS cannot act on it and this id will still be sent/retrieved by our servers, even though the user is in opt-out for example.