@irl

Regarding stable IPv6 addresses - they are pain to configure as you have to use DHCPv6 and DHCP simply makes little sense with SLAAC. I've spent significant amount of time configuring DHCPv6 only to be able to track traffic in my LAN as all my personal and kids devices had different IPv6 addr each time :)

At the end of the day, I'm just tracking their MAC addresses as these are stable and configured everything else to use privacy extensions.