Hey @psynthesis
If you are using Cloudflare to manage DNS, there is no need to put the CF nameservers anywhere on Netlify. You will need to following the Configure external DNS for a custom domain | Netlify Docs documentation by creating flattened CNAME/A record for the apex, and CNAME for the www subdomain in the Cloudflare domain management.
Do also have a read through the following support guide on possibly issues with using Cloudflare in front of Netilfy and how ensure these issues don’t occur