> Local DNS is commonly recommended with ipv6 for that reason, which maybe is just some misguided advice because it sounds crazy.

Many (most?) SOHO routers already run a combined DHCP and DNS server called 'dnsmasq', which supports DHCPv6. IIRC, dnsmasq automatically adds DNS records for hosts to which it gives out a lease. Android computers don't use DHCPv6, so this won't help you access them by name, but how often do you care to directly access an Android computer?