Facet paths can't be altered by facet alter callbacks

Hi,

Implementing hook_facetapi_facet_info to add a custom alter callback for a facet works great.

However, modifications done to the #path index in the render array aren't possible, since this gets overwritten (again) in the processQueryStrings method, called in last place by FacetapiFacetProcessor::process()
@file plugins/facetapi/adapter.inc
@line 1619

  protected function processQueryStrings(array &$build) {
      ...
      $item['#path'] = $this->getFacetPath($values, $item['#active']); // This is where the overriding happens
      ...
    }
  }

Any ideas on how this could be fixed? (Withouth implementing a whole new URL Processor...)