Android TV app on Sony Bravia TV, some questions

Hi,

Recently I bought a new Sony Bravia 65XE9005 (X900E) LCD TV which runs the latest Android TV version 7.0. There are two things that I noticed with the Plex for Android TV app.

1. All files are being transcoded by my PMS. No direct play at all. I've configured the app to do direct play/stream.
2. Dolby Digital 5.1 streams are transcoded to stereo when using the optical out on the TV to a soundbar.

So, why is this Plex for Android TV app on a Sony TV transcoding everything while the Sony supports all of the popular formats and codecs? For example, the Netflix app nicely outputs DD 5.1 over optical, so this is a working feature.

Transcoding is a nogo for me because this brand new 2017 Sony model supports every modern codec and container. Is it possible a Plex developer could explain why this occurs on Sony Android TV's?

Plex for Android TV version is 6.6.0
PMS is version 1.9.5.4339