Plex currently only allow language indication for audio tracks and subtitles. As I am sure many will agree, this is not enough for some cases. Audio commentary for example, falls under this case. The main audio track and the commentary are generally in the same language, which Plex simply shows the video with two audio tracks of the same language. The viewer has no idea which track to choose, this becomes greater problem if there are more than one audio commentary tracks.
Same goes for the subtitles. If one needs the subtitles for audio tracks (as well as the main audio track), one will obviously want them both in the same language. Again, the viewer has to check each one before getting the right one. Just like the language indicator you put at the end of file name, perhaps another indicator can be placed.
"Game of Thrones S2E03.EN.Commentary.srt" Something like that and PMS can read and display accordingly.
