> In practice, nobody uses IPv6 for printers, so it'll work just fine over IPv4.

I bought a HP printer 6 years ago, configured it to connect to my WiFi and it automagically became available on my Mac. It advertises itself over mDNS and my Mac talks to it over IPv6 link-local.

All of this happened without any special configuration changes. I’m pretty sure quite a few people around the world print over IPv6 without even knowing that.