but firefox has different dns requests going to their servers as well.
Even if that works, it'll likely get patched out eventually with a forced update.
If you do insist on using Windows, an external firewall is the only way to be sure. But even that isn't foolproof since another update may decide that your Windows license isn't valid unless the analytics server is reachable.
If you want to block it from things you don't trust to have such methods (or always listen to them) you'll have to upgrade to a firewall that can filter outbound connections to IPs the client hasn't received a DNS response for or require use of an explicit HTTP proxy for outbound connectivity.
Just blocking DNS can be a good middle ground for reasonable effectiveness without as much effort.
A few of them actually do make sense for a normal user (i.e. the Wifi portal stuff). But you can disable it if you spend some effort on it or you can also use an alternative build of Firefox without it. Not great, but also not terrible imo. Sorry, that I have no English source.