Yeah, I fully understand what you’re saying… The entire reason for me doing my library the way I have was to reduce transcodes, and allow more streams… I mean even removing the whole “Green energy” Argument, it’s still money savings, and significant money savings at that if you have a larger userbase and content library. It’s one of the reasons I made a “Feature Request” which can be seen here: Dynamic Video, Audio, and Subtitle Selection by PMS/Plex Client, and "Use with Foreign Audio" tweak
This isn’t a solution for everyone, obviously, as most people don’t have large enough disk space to store all of the necessary information, but at the moment I am at 72TB and will be over 130TB by the end of the year, so it’s the way I would tackle the problem if I was Plex. Because mutliplexing takes almost no power to accomplish… and if they would enable multi-video stream matroska files, it wouldn’t even need to multiplex anymore, it would just do everything it needed to do and DirectPlay it all day long…