While not to the degree of “immediate total halt” when backgrounders, https://developer.mozilla.org/en-US/docs/Web/API/Page_Visibility_API https://developer.moz

While not to the degree of “immediate total halt” when backgrounders, https://developer.mozilla.org/en-US/docs/Web/API/Page_Visibility_API https://developer.mozilla.org/en-US/docs/Web/API/Page_Visibi... may be of interest for understanding what kind of background throttling may be in place for all tabs.