It would be great to be able to use subzone delegation.
For example, if you need a seperate nameserver to handle DNS lookups for a specific subdomain only. There are a lot of cases where this is useful.
I want to move away from my current provider (Linode), but I'm unable to add NS records for a specific subdomain - only for the whole domain.
Maybe add a second text box when adding an NS record, labelled 'subdomain'?