Thanks @CJLocos for the post.
I checked today and found that finally multi-channel playback via PMP works in native resolution (I checked up to 5.1 with 24/96, e.g. Setup 2).
This is great and closes (part of) the pain-point outlined in my original post. Happy for the progress (albeit 1 year later).
Checked again playback on Nvidia Shield and there the situation remains unresolved.
No high-res multichannel, and no highres stereo either (e.g. Setup 1).
Though grateful for the progress. I was looking into Roon as a alternative for audio, but its inconvenient to switch between different playback solutions depending on the content.
