How to disable sound effect on achievement toast?

[Hexerin]

Disclaimer: I'm running the Steam beta client, so this may be something you need to be opted into that to be seeing.

Just noticed a sound effect when getting an achievement, this has never happened before. As I generally dislike sound effects on toasts, I would like to know how to disable this. I looked under the notifications settings in the Steam settings (the logical place such a toggle would be), but there's nothing there for achievement toasts.

[Crazy Tiger]

There is only a general setting under notifications, which disables all notification sounds: https://imgur.com/a/1WXMTg8

[ERROR_MACRO]

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[Electrolyte]

I don't understand how many years we have to wait for a simple lever to turn off the achievement toast and/or its sounds. Every other toast has an option to turn off the toast in question, but if you want to turn off the achievement toast, noup, turn off everything.

I made a .bat that overwrites the sound file to nothing so that at least I can get rid of the sound, but that also has to be executed every time steam starts because it restores the sound file back.