On November 12, 2020 at 02:18, Lyndel McGee said...
If you learn a remote on the Apple TV 4k, the code you teach for 'Next', Play symbol + vertical bar '|', will function as the Home key with a Short Press. If you press this button for an extended duration, you will be taken to the 'Sleep' Menu.
TVOS 14.3 has removed this capability. They also removed the ability to put the unit to sleep using a learned 'Stop' command.