Aside from USB playback, an Apple TV 4K can solve most of this. (I don’t know about Spotify Connect but assume it works with AirPlay if not).
I suppose the TV can still use the pendrive even offline, actually.
What advantages does an AppleTV 4K (£169) have over a Roku Streaming Stick+ (£45)?
It works quite well even when my phone is streaming media that's on cloud storage somewhere (nPlayer supports many). But for optimal playback I download the file to my device first.
Of course if you want Dolby Atmos sound, I think you're out of luck. I think HDR should work but not sure.
[0] https://apps.apple.com/us/app/nplayer-plus/id539397400#?plat...
edit: You can also install app on the ATV that accesses files stored over the network/internet as well, like VLC for ATV. Though I've never found a great one.
Isn't that covered by your airplay requirement?
If you have a solution I'm all ears!
My understanding is that it supports 4k and a range of streaming devices but I can’t say if it handles it flawlessly because I don’t have hardware to try it.
I have a 28.99GB H.265 5.1 Atmos MKV file of Linux tutorials that I would like to play on it, sitting on my MacBook.
What is the most painless way to play it on the Apple TV with no loss of quality (other than the surround, which will be played on 2.0 speakers anyway).