What about this use case:
- Specify a list of domains resolved by the nameservers proposed by DHCP
- For the rest, use the list of nameservers you defined.
What about this use case:
You want conditional forwarding (e.g. http://forum.mikrotik.com/t/feature-request-advanced-dns-server/94287/42), welcome to the club. If RouterOS could do this, then even without any extra support for DHCP, you could use lease script to make it work with dynamic servers.
Yes, someone may want to to the reverse: default to DHCP, look up specific domains in other nameservers.