Managed DNS Platform only

Hey folks, I"m quite new to cpanel so sorry for asking too basic questions. I want to build a Managed DNS Hosting Service where people can get users accounts on my cpanel landscape and only use my DNS. Add external domains, use my dns servers to create and manage all dns settings. Idea is to create one main cpanel server and 4 additional vps based "dnsonly" ones in addition. (How) would work overall?