Not really an [issue], but I'm setting up a new computer, and want to copy my muted sounds from one to the other. Is there a way to access the list via notepad or something, rather than going in-game and writing down all my muted sound IDs?

You can copy your entire WTF folder if you just want the same configuration for everything on the new machine. If you want only this addon's configuration, you can find it in the WTF folder's structure in lua format.

Indeed, copying the WTF folder is the only option. Going to leave this open as a suggestion for in-game copy functionality.