File entity doesn't support byte ranges

I have site offering large mp4 files for sale via commerce file, but served wrapped in video tags. The video tag src maps to a file/{fid}/download?token={token} URI.

File entity file_entity_download_page() outputs 'Accept-Ranges' => 'bytes' that causes browsers like Chrome to request the video file in chunks. However, file_entity_download_page() then routes to core's file_transfer() that doesn't support byte ranges. Compare to the logic in _resumable_download() from https://drupal.org/project/resumable_download