We don't officially support Cloudflare on our webhosting. If you were to add your domain to our webhosting using our nameservers and then switch back to Cloudflare, this would allow the site to load. Any future domain or subdomain changes would require the same process. Using Cloudflare would also break our Let's Encrypt SSL setup, not allowing your site to load via HTTPS.
We also generally recommend against using CloudFlare with our webhosting because it can degrade site performance, security, usability, and DDoS mitigation, and because CloudFlare can insert interstitial ads and alter its proxied output in various ways.