Sony BDP-S6200: Help with audio and subtitle

First of all, a big thanks to all the developers and people involved in making Serviio the best DLNA server solution. I’ve tried a few different servers but Serviio is the one that works with no mess, no fuss.

I recently bought a Sony BDP-S6200 and found that it can play most files over DLNA natively. I have a couple of questions about tweaking the “Sony BDP-Sx100 (2013)” profile I’m using.

1. What do I need to add/change so that DTS-HD and Dolby TrueHD is passed through as is, rather than being transcoded to PCM?

2. I understand Serviio doesn’t support PGS subtitles yet, but they are recognized and selectable (along with audio tracks) by my BR player in a MT2S container. The only problem with this format is that chapters are not supported and closes the file if I press “next” accidentally. (FF/RW works fine.)

In an MKV container, everything works fine as they should, except the embedded subtitles do not display on screen. When the subtitle button is pressed, it shows the tracks being present and can be selected, but they just don’t show up on screen. I’m wondering how MT2S and MKV handle PGS tracks since they show up in one format but not another.

Do you have any ideas or comments as to what I could try to fix both/either the chapters problem with MT2S or the subtitle one with MKV?