Red Flag Domains are lists of very recently registered probably malicious domain names in french TLDs (see here). Data are published for security purposes only, and can be used to feed an automatic filtering solution like proxy.

There's been a fair bit of controversy over DNS-over-HTTPS (DoH) vs DNS-over-TLS (DoT), and some of those arguments still rage on.

But, DoH isn't currently going anywhere, and Firefox has directly implemented support (though it calls them Trusted Recursive Resolvers or TRR for short).

Installation et configuration de Dnsfilter sous Android (https://f-droid.org/fr/packages/dnsfilter.android/)

Mozilla cherche à renforcer la vie privée des utilisateurs de son navigateur Open Source en chiffrant les requêtes DNS, en ayant recours aux serveurs publics de la société Cloudflare. Cette fonctionnalité est désormais disponible dans Firefox.