OpenBSD makes it easy to try IPv6 tunnelbroker.net with NAT64/DNS64 if your ISP only has IPv4 ("one more lab test away.." they say).

This has worked for me well for a couple years. I do use a VLAN to keep the IPv6-only network separate (homelab) from video streamers in the household.

In my pf.conf:

    # IPv6 tunnel
    block in log on $tun6_if all
    block in quick on $tun6_if inet6 from fd00::/8 to any
    antispoof quick for $tun6_if
    # allowed icmp6
    pass in quick log on $tun6_if inet6 proto icmp6 icmp6-type {
        unreach, toobig, timex, paramprob, echoreq
    }
    # MSS clamping 60 bytes less than HE 1480
    # 20 byte IPv4 tcp header + 40 byte IPv6 ip header
    match on $tun6_if all scrub (random-id max-mss 1420)

and in /var/unbound/etc/unbound.conf:

    # DNS64/NAT64
    module-config: "dns64 validator iterator"
    dns64-prefix: 64:ff9b::/96

Done. I don't have 464XLAT on Win11 but I do want to know if there's a hard coded IPv4 address anyway. I never had an issue.