Update. Ran a quick test with a FLAC 4.0 96kHz/24-bit music file.
Plex Media Server direct plays, but the Shield sends it to my receiver as PCM 2.0. Also, it is sent as 48kHz. Not sure about bit depth, as the receiver does not show that info (using the Denon app on my tablet to view channel mapping, bit rate, etc).
So, if multi-channel FLAC for music is a requirement, looks like the Plex Android TV app on the Shield will not work.
