@Grey I think you are missing a key element. Over the HDMI, there is alway audio AND video active to the monitor. This is the point. Its ALWAYS there.
The discussion raises, on pristine distro boot on a PC using HDMI, that WE know audio is there and consideration is asked "shouldn't it be on as the default sound device at boot?" In HDMI and in DP all TVs and many monitors have speakers always active. There remains no confusion ... excepting that, today, audio is overlooked in this case...even though the technology has been around for over a decade.
I dont know if you are willing to see it this way or what ... and is the reason I ask "???".
Lastly, no one here, is denying that IF SPEAKER are also wired to the PC, then a user DOES get audio by default. This technology has been around since before the turn of the century. And it is well understood in Puppyland. As well, in the past, this was the only option and became the default.
But, today, users can come to Puppyland for distros with a PC that ONLY has one cable feed to its monitor which carries audio signaling along with the video signal. In Puppyland, this is overlooked and an oversight.
There is NO guessing. If you see HDMI, then know that there is audio presence in all cases for pristine use. There is no failure in operation.
Is this explained clearly?
P.S. Something tells me you know this, and I may be missing something you know but are not presenting. If that is true help with what you are proposing, please.