Unable to use hook_apachesolr_update_index with apache solr attachments

I have been using hook_apachesolr_update_index() to fine tune access control in my searches. As I am using the private_upload.module, I need to be able to add more control over attachment searches.

The process for doing this in apachesolr is to use hook_apachesolr_update_index() to add a dynamic field to a document, then hook_apachesolr_modify_query() to filter on this field. See http://drupal.org/node/632962 for more details on this.

The problem I am having with apache solr attachments is that in it's function apachesolr_attachments_add_documents(&$documents, $nid), it by passes the hook_apachesolr_update_index() process, except for apachesolr_nodeaccess. Here is the code:

        if (module_exists('apachesolr_nodeaccess')) {
          apachesolr_nodeaccess_apachesolr_update_index($document, $node);
        }

As a result, any other module's hook_apachesolr_update_index() code is ignored.

A simple hack for this is as follows:

        if (module_exists('apachesolr_nodeaccess')) {
          apachesolr_nodeaccess_apachesolr_update_index($document, $node);
          mymodule_apachesolr_update_index($document, $node);
        }

My question is: Wouldn't it be better to call all hook_apachesolr_update_index() functions as provided for in apachesolr.index.inc?:

    // Let modules add to the document - TODO convert to drupal_alter().
    foreach (module_implements('apachesolr_update_index') as $module) {
      $function = $module .'_apachesolr_update_index';
      $function($document, $node);
    }

Or, is there a reason why this was not implemented originally?