dunno… I have my own private decks and if I use shared ones I would like for them to be as “pure information” as possible without anything “special”…
Templates are not that difficult but only having plain-text editor definitely makes them harder to work with 
Yeah, you are right. I was thinking about some actually using it directly in the field.
Though if it’s in the template applied to the field then… having a field configuration option would be nicer/better - don’t you think?
The advantage is that in this case you can apply it to the whole field in the template. And separately for each audio file. Alternatively, you can set up one behavior in the template for card type 1 and another for card type 2. What you are suggesting is not flexible and useless to me.
It’s also just a complication of the user interface.
Look here, if you haven’t already:
https://forums.ankiweb.net/t/controlling-display-and-function-of-audio-buttons/10234
It’s not exactly what you’re looking for but it might be helpful and work with some tweaks.