Usually in many simple hosting setups (where W3TC is common) the reloading of nginx is left to a cron job at some set interval. Other plugins like iThemes Secu

Usually in many simple hosting setups (where W3TC is common) the reloading of nginx is left to a cron job at some set interval. Other plugins like iThemes Security will populate the nginx.conf with banned IP and the such, so it can update on a fairly regular basis.