Worry about IPv6 leases and DUID in script-storage.

dhcpv6-range
dhcpv6-option
dhcpv6-option-force
dhcpv6-script ?
dhcpv6-optsfile
dhcpv6-hostsfile

dhcp-host =
[<hwaddr>][,id:<client_id>|*][,net:<netid>][,<ipv4addr>][\[ipv6addr\]][,<hostname>][,<lease_time>][,ignore]

IPv6 address like [2001:db8:do::2]