Using custom field data specified with hook_civicrm_customFieldOptions in reports

Is use the hook_civicrm_customFieldOptions to load all (drupal-) taxonomy terms of a specified vocabulary in a (civicrm- ) custom field added to an activity. This works as expected. When a user adds a term to the vocabulary, he can use this term in the custom civicrm-field. However...

When I want to make an activity-report, the label of the field is displayed, but no data of the field is displayed (empty result or not able to filter). To hook hook_civicrm_customFieldOptions to load is not used.

I think this is a feature request ?

Or maybe I should work the other way around and implement a hook_taxonomy to save the new term in the civicrm_option_value table ?