That doesn't work if the user manually enables DoH: > Note: The canary domain only applies to users who have DoH enabled as the default option. It does not app

That doesn't work if the user manually enables DoH: > Note: The canary domain only applies to users who have DoH enabled as the default option. It does not apply for users who have made the choice to turn on DoH by themselves. https://support.mozilla.org/en-US/kb/canary-domain-use-application-dnsnet https://support.mozilla.org/en-US/kb/canary-domain-use-appli...