Read Only NS record

[#1]

What I am trying to do.

I am switching storage hardware. I have a delegation for a zone with an associated read-only NS record. I want to re-use the zone naming so end users don't have to change anything. The new configuration will be a direct A record.

What my question is:
Doring cut-over I want to disable the delegation. If I do will the NS record also be disabled or will I need to delete the record.

If I have to roll back, Will the NS record be re-created when I un-check the disable on the delegation?

Thanks in advance

[#2]

Assuming you have the zone delegated to another server, if you delete the delegation and replace it with an a record, that will resolve as you expect.

The question is: are their any records on the actual authoritative server for the subdomain you are delegating to? All those records would become unresolvable by any system using this appliance for DNS .