> addressing hosts via IPv6 is the wrong way to go about it. On your lan, you really want to be doing ".local" / ".lan" / ".home".
.local is fine as long as all the daemons work correctly, but AFAIK there's no way to have SLAAC and put hosts in "normal" internal DNS, so .lan/.home/.internal are probably out.
I do it by abusing the static slaac address. I have a set of wierd vms where they are cloned from a reference image, so no fixed config allowed. I should have probably just have used dhcp6 but I started by trying slaac and the static address were stable enough for my purposes so it stuck.
> On your lan, you really want to be doing ".local" / ".lan" / ".home".
The "official" is home.arpa according to RFC 8375 [1]:
[1]: https://datatracker.ietf.org/doc/html/rfc8375