public function __construct() {
          // Stop any PDFs from being immediately generated (require Gravity Forms Delayed Email Notifications)
          add_filter( 'gfpdf_maybe_attach_to_notification', array( $this, 'require_delayed_notifications' ), 10, 5 );
     }

     public function require_delayed_notifications( $attach, $notification, $settings, $entry, $form )  {

          // Disable Gravity PDF attachment if the notification has a flag (__AFTER_DELAY_FLAG__) letting us know that this notification is supposed to wait until after the delay
          if ( preg_match( '/__AFTER_DELAY_FLAG__/', $notification['subject'] ) ) {
               return false;
          }

          return $attach;
     }