Reverse entity references *and* file attachments?

Is there a way to combine "Reverse entity references" and "File attachments"? The usage examples in are for direct file and media fields directly on the indexed content, but in my case I have File media entities with PDFs that reference content nodes. If I use the Reverse entity reference processor I can see the media field in the Search API "Add fields" dialog and choose (say) search_api_reverse_entity_references_media__field_media_of:field_media_file but the full text is not indexed, only the file id; solr shows "tem_field_media_file":["2"],