The maximum waiting time equals the session lifetime configured in the Joomla! global configuration.
To see the waiting time message AND to make the plug-in function properly, you must also activate the so-called OVERRIDES. In many cases, this can be done by enabling the authentication and user plug-ins and then logging into the FRONT-END as a SUPER USER; you need to do this only once. See the documentation in the downloaded package if this does not give the desired effect.