Facets summary block themer experience

Hi,

i have included facets summary block in a project with so much front en markup customization and i have found at least a big issue with themer experience. Current implementation of DefaultFacetsSummaryManager use this in build method:

$build = array(
      '#theme' => 'item_list',
      '#attributes' => array(
        'data-drupal-facets-summary-id' => $facets_summary->id(),
      ),
    );

i cannot customize markup of hole summary list to change UL tag or add classes to items. I cannot found a way to change it using preprocess_item_list or theme suggestion. I ended overriding DefaultFacetsSummaryManager service with a custom one to control this theme function. I think that is more flexible to use a custom theme twig file for this list.

Best!
David