Simplifying State Dependent Images or Entities in Lovelace YAML

I have this:

            - entity: media_player.denon_zone4
              state_image:
                on: /local/icon_on.png
                paused: /local/icon_off.png
                playing: /local/icon_off.png
                idle: /local/icon_off.png
                off: /local/icon_off.png
                unknown: /local/icon_off.png

I need something like this:

            - entity: media_player.denon_zone4
              state_image:
                'on': /local/icon_on.png
                not 'on': /local/icon_off.png

Is there a way to avoid referencing all possible states when your focus is on one particular state? I’ve got 11 different speaker zones so I want to keep my code as simple and as short as possible, and in this case only 1 of 6 states should change the image I want displayed. Thinking I need an “state_not” type of declaration but I’ve not found anything that would work.

Additionally, I can’t find a way to setup a state_image type entity where there is no image if not expressly stated. IE, If state is “off”, show the power button, otherwise show nothing.

What am I missing?