That doesn't quite work, because the premise of accessing a router setup page is that your internet connection doesn't work yet. So your router has to be able t

That doesn't quite work, because the premise of accessing a router setup page is that your internet connection doesn't work yet. So your router has to be able to prove its identity to the client entirely offline. (You cannot special-case "This server is untraceable", else a repressive government could blackhole that server and trigger the relaxed validation rules.)