After I can host a Minecraft server in my home (with no static IPv6 address), and I have a domain hosted at Cloudflare, I suddenly realized instead of using the tunnel, which introduces latency, I can update the record based on my dynamic but global IPv6 address!
My friends were no longer required to update the server addresses everytime my ISP assigned me a new one.
It's not hard to call HTTP API using curl and parse the result using jq.
I love IPv6 (but still I need to disable my router's firewall)
And guns are so good in Minecraft. Now I can go to the caves and start mining without getting scared by creepers.
Mod: https://modrinth.com/mod/timeless-and-classics-zero