@virgiliomi
I've had the same prefix since that setting was added, about 2 years ago IIRC. That's stable enough for me. On IPv4, my host name is based on firewall & cable modem MAC addresses and so never changes unless I change hardware. This means that no matter what my IPv4 address is, I can still find my network. However, my IPv4 address is also stable, so long as I leave my firewall running, other than the rare occasion when my ISP makes network changes.