FYI, consider this a PSA:
Don't bother using Atmos for games. Why? Because a/v sync issues. It's really obvious how much a/v sync lag there is with Bitstream enabled. You can even test for yourself. Currently, EVERYONE connecting an XBOX One S to their TV via the HT-ST5000 should not be using Bitstream. I have mine set to PCM 7.1.
Test for yourself: Leave the XBOX One S set to PCM 7.1, and move the controller around the menu options so you can hear the little sound effect "BLIP" as you move between tiles, options etc. See how it's dead on perfect?
Now switch the XBOX One S to Bitstream/Atmos, and do the same thing. See how the sound now lags behind the video by.. (I'm guessing) 30-50ms? If you're not sensitive to this, then - fine. But I am, and it's really frustrating.
Be nice if we could have separate audio settings for Blu-ray MOVIES vs games. Then you could get Atmos from the 4K UHD Blu-rays, but not deal with the audio lag for games. Currently, the only way to deal with this is to switch Atmos/Bitstream on for 4K UHD Blu-rays, and then turn that OFF when playing a game. Ugh..
Media should never have any issue with the above mentioned a/v sync lag with bitstream, because non-interactive media (i.e. movies in this case) is synced up at the start of the stream. For games, this isn't the case.