T-Mobile doesn’t support IPv4

I use unbound forward DNS over TLS to nextdns, I try to keep it simple.

That’s why you use a TMP drive for cache, a ram disk or on Linux store cache in tmpfs.

Linux comes with a default firewall it’s called IPtables/NFtables, Just make sure that it’s on. Example I Ubuntu Sudo ufw enable.

Firefox with Ublock Origin, Router forwarded DNS over TLS to NextDNS. Plus firewall rules to forward all DNS from LAN to the router, on mobile same browser and using Android native DNS over TLS forward to NextDNS

Firefox for me,been using FF since VER 1.0 days.