I'm glad to hear that the improved DTS-HD-MA passthrough is working for you. This will work if you are Direct Playing your MKV file, but will not if you require it to be transcoded (e.g. when lowering video quality). We'll hopefully be able to resolve that in the future.
As for TrueHD , that is on going work. I've written up my findings of TrueHD for both Google and Nvidia and there requires some additional work in order to support it . We'll continue to push for support, but at the moment, it's out of our hands.
I just want regular DTS to work correctly on my Sony Android TV. ATM anything with DTS either doesn't play audio at all if passthru is enabled, or it gets downmixed to stereo if its disabled, which is disappointing. I don't know why there isn't an option to just transcode it all to AC3 if the DTS decoder is broken.