Some testing has already happened before starting the rollout. The change has been shipping in Firefox Nightly for a year. I have analyzed impact of affected p

Some testing has already happened before starting the rollout. The change has been shipping in Firefox Nightly for a year. I have analyzed impact of affected pages in the HTTP Archive dataset (about 12,000,000 pages), twice: https://github.com/whatwg/html/issues/7867#issuecomment-1977647444 https://github.com/whatwg/html/issues/7867#issuecomment-1977... https://github.com/whatwg/html/issues/7867#issuecomment-2595987424 https://github.com/whatwg/html/issues/7867#issuecomment-2595... The next step is either rollout or ship directly.