Fairly reliable until very recently. A 2025 firefox updae may have been it's end. It no longer detects properly, most often muting ads and remaining muted. Sometimes doing nothing at all.

Doesn't seem to be working anymore. At first it stopped unmuting ads after they were over, but now it seems to do nothing at all.

Works half the time, very inconsistent.

Response to the dev -
It's completely random. sometimes it works and other times it doesn't, will post an update if i find out anything. Perhaps it could have an issue with another twitch extension i have, BetterTTV, FrankerFacez, Unwanted Twitch.

Update 31/5/24 -
Still randomly decides to play audio in an ad, i disabled the extensions mentioned above and issue remains, have no idea what is causing it, it's completely random. I would say it mutes 90% of the time but then randomly an ad will start playing with sound, very annoying. To fix it i usually have to fiddle about with restarting the page and disabling/enabling the extension.

You mentioned multiple tabs, not sure if that is still the issue or if you have actually fixed it, i always have multiple tabs open in Firefox, at least two at any given time, so perhaps it's still causing an issue.