Not sure if I mentioned it in one of my long winded posts, but check the Apple TV’s Music app settings. If you want Lossless two channel versions at all times and no lossy Dolby Atmos or Dolby Audio(5.1) versions played, switch the Dolby Atmos setting in the Music app to OFF. When it is set to Automatic, the Dolby Atmos and Dolby Audio versions will play by default.
If the receiver sound mode is set to Stereo, it will output sound from just the front speakers when playing Dolby Atmos or Dolby Audio versions. You will notice what seems like a lack of dynamics because they do come in at lower volume compared to the Lossless versions.
To make the settings adjustments, go to Settings>Apps>Music>Audio and turn Dolby Atmos OFF. Then, make sure Lossless ALAC is selected in Audio Quality, not High Quality AAC.
Below those two settings is the Sound Check setting. Leave it OFF. It will level out the volume of all music so nothing comes on too loud and all play at the same volume
. But, it levels them out at the lower volume track levels and louder tracks get gimped. I leave it OFF myself.