EricLuehrsen:

As a lift from dnsmasq behavior, allow the option 'dns' to configure to the prefixes on the interface. If its [::] it will use the GA of the router, if its [fd00::] it will use the ULA, if its [fe80::] as-is default, and just host ID parts append to all prefixes such as [::53]. The later to direct to a standalone server. IPV6 prefixes can shift at your ISP will, and setting a static dns option for odhcpd to communicate either "this router" or "device ::53" is not self sustaining. Also the link addresses are really for lower level network management, and application levels should be GA or ULA. Some client devices/OS will not use LL.