When a dhcpv6 client requests a prefix, it would be nice if dhcpd could add an ipv6 route to that prefix via the link-local address of the requesting client. And when lease expires, just remove that route.
dhcpv6-relay should also have this option.
This makes provisioning ipv6 network to subscribers much easier as one doesn't have to use a routing protocol to reach the delegated prefixes.
Mikrotik RouterOS has this feature, but I'm not sure if there is an option in dhcpd.