Did something change with the Apple TV app?
I got a Apple TV little over a month ago, and I recall when i compared it to my Shield, it had the option on the top tool bar to "Reduce Loud Sounds" that is the native Apple TV volume leveling feature.
That option appears in all my streaming apps, but for some reason, I notice is not present in Channels.
I am pretty sure it was there before.
I can activate it on the system level via System settings, but that is a pain, and I only want to activate it when i need it on-demand, and per app.