Feature request: HDMI Audio: Add inaudible AVR keepalive signal to keep audio devices alive

I have a TV with a soundbar connected over TOSLink (S/PDIF). The soundbar is very sensitive to even brief silences (-inf dB levels), and will fall asleep, and when a sound begins, it takes roughly 200ms for the soundbar to wake back up, which means small sounds can get lost. For example, in Portal 2, during GlaDOS' song at the very end, she sings the following lines:

Goodbye my only friend.
Oh... did you think I meant you?

The words that are stricken out are missed by my soundbar because of the surrounding silence.

I know it's quite a niche issue, but I've noticed several areas where the absence of audio causes issues sometimes. In particular, my upstairs TV: if, for example, I'm navigating through the menus in Big Picture Mode, the respective UI sounds play, but right after they stop, no signal is sent to the TV. It's like turning a switch on and off again in rapid succession. If that happens enough on this TV, the audio will eventually become garbled until I power-cycle the TV.

The solution? Play a constant, inaudible random noise over connected HDMI devices, which will keep them awake, and include a setting where the feature can be toggled—preferably in the Audio settings page in Steam Big Picture Mode. The sound should be disabled when using the Deck's internal speakers, for example, or when using an audio device connected directly to the device's analog output jack.

Now, HDMI devices are kinda smart, and sending a silent (zero) signal expecting that just keeping the audio stream open will keep the TV/AVR/soundbar alive is not enough; it needs to be random, inaudible noise louder than -inf dB. Developers can take a look at Kodi's implementation of the same feature in their media center suite, which they refer to as "Keep audio device alive."

Perhaps this is something better suited for Steam's Big Picture mode rather than SteamOS itself, but either way, it would be very useful for someone like me with older, dumb equipment.

Start by reviewing Kodi's linked “Keep audio device alive” implementation, then locate Steam Big Picture Mode's Audio settings and the HDMI audio output path. Define how the toggle applies to HDMI devices while excluding internal speakers and analog output, and verify that the keepalive signal prevents connected equipment from sleeping without being audible.