The Shield is not properly detected by PMS, and therefore a lot of stuff gets transcoded when it doesn’t need to. A proper client profile XML file would solve this, and since the Shield is also a potential Plex server it seems like making it a 1st rate client is a no-brainer.
A profile for the Shield is already pretty much done, just need to transcode to flac for MusicProfile to be perfect.
forums.plex.tv/discussion/285204/shield-tv-player-xml-profile
Early 2021 clean-up: implemented