first of all thanks for this plugin. I looked for something like this for years, I tried many similar plugins but none was fitting my needs except yours.
However I'd like to have an additional feature, which I believe would have a general purpose use. WordPress API actually has two different media frames, "post" and "select". The second one is often used by themes and plugins for selecting items from the media library. I.e. it is used by many themes (including the current default WP theme Twenty Fourteen) for the selection of the site header image in theme options. Unfortunately when using this "select" media window, the category/taxonomy filters provided by your plugin do not appear in the media browser, so it's not possible to filter the items.
Would it be possible to let your plugin handle that too?