After many years of having a home theater I now have something that is almost perfect. The only thing missing is the ability to control the volume of my system from Plex Companion.
I use iRule on my Android tablet to automate the turning on of components, switching inputs and controlling my receiver. Clicking one button will also start my PC and open Plex Media Player and then launch Plex on my tablet in “Plex Companion” mode.
Everything is almost good. However, there is no way to control the volume of the receiver from Plex Companion other than switching applications in the android to a page in iRule that has a volume control.
I know that using the volume buttons in the Android will increase and lower the volume of what you are viewing. However, this only can work up to whatever the amp is set to. So if the volume is too low, you need to use another remote to raise it. You can then lower it with the plex app. However this does not actually change the volume on the receiver.
So basically, a new feature could be to allow Plex Companion to adjust receiver volume using CEC.