Just another idea from lil old me :rolleyes:
I know content of this variety is in a minority compared to other formats, however its the one format that seems to prevent Plex from 'covering all bases'.
I've read that support for this has been incorperated into more recent versions of ffmpeg (read about this on XBMC forum since they also leverage ffmpeg).
Would be great to see this in Plex too!