Customise default /nagios callback

Code example from prod_check:

settings page:
<?php
    $form['prod_check_nagios']['nagios']['settings']['prod_check_nagios_takeover'] = array(
      '#type' => 'textfield',
      '#title' =>   t('Custom Nagios path'),
      '#description' => t('If you wish to use a different path than the default /nagios path enabled by the Nagios module, then enter the desired path here. Leave blank to do disable the takover.'),
      '#default_value' => variable_get('prod_check_nagios_takeover', ''),
      '#required' => FALSE,
    );

    $form['prod_check_nagios']['nagios']['settings']['prod_check_nagios_unique'] = array(
      '#type' => 'select',
      '#title' =>   t('When Nagios unique ID not recieved'),
      '#description' => t('Select what should happen when the Nagios unique ID is not recieved by the nagios page.'),
      '#options' => array(
        'default' => t('default Nagios module behavior'),
        '404' => t('throw a 404 error'),
        'home' => t('redirect to homepege'),
      ),
      '#default_value' => variable_get('prod_check_nagios_unique', 'default'),
      '#required' => FALSE,
    );
?>

callback override:
<?php
/**
 * Implementation of hook_menu()
 */
function prod_check_menu_alter(&$items) {
  if (variable_get('prod_check_enable_nagios', 0) && isset($items['nagios'])) {
    // Change callback.
    if (variable_get('prod_check_nagios_unique', 'default') != 'default') {
      $items['nagios']['page callback'] = 'prod_check_nagios_status_page';
    }
    // Change the path.
    $new_path = variable_get('prod_check_nagios_takeover', '');
    if (!empty($new_path)) {
      // Create custom Nagios path.
      $items[$new_path] = $items['nagios'];
      // Drop old Nagios path.
      unset($items['nagios']);
    }
  }
}

/**
 * Custom callback to override /nagios page.
 */
function prod_check_nagios_status_page() {
  if ($_SERVER['HTTP_USER_AGENT'] != variable_get('nagios_ua', 'Nagios')) {
    switch (variable_get('prod_check_nagios_unique', 'default')) {
      case '404': drupal_not_found();
        break;
      case 'home': drupal_goto('<front>');
        break;
      default: nagios_status_page();
    }
  }
  else {
    nagios_status_page();
  }
}
?>

I'm happy to make a patch if this functionality is wanted enough.