This functionality is available for PRO version.

Name: wph/components/block_wp_cron_php/local_ips
Type: Filter
Arguments:
(array) $local_ips

This filter can be used to add IP’s to ignore list for which the default wp-cron.php file can still be accessible when blocking the default.

    add_filter( 'wph/components/block_wp_cron_php/local_ips', '__wph_components_block_wp_cron_php_local_ips' );
    function __wph_components_block_wp_cron_php_local_ips( $local_ips )
        {
            
            $local_ips[]    =   '192.168.0.1';
            
            return $local_ips;
        } 

Important!
The above code should be placed within wp-content/mu-plugins/ directory.