Agree about Jilas View.
You should be able to add buttons/actions, in the IN/OUT Activities. The same functionality you have in the power button.
Basically, you add a list of actions when you enter the activity, and if you want a list of actions when you exit the activity (IE: Turn off something).
IE: If you press A,
Enter Activities: HDMI1 on TV and turn on the XBOX.
Exit Activities: Could be turn-off the XBOX.
If you press B,
.......Exit activity from A will be triggered if any.
Enter Activities: TV, HDMI 2, and turn on Shield.
and so-on
In fact, if it was me, will recommend reducing the scope, of the on/off button, to turn on the tv, and enter the last activity user used when off, exit the activity, and turn off the TV when off.
Up to the user to select if the power button belongs to the activities, or is global.
