I think it will be better to fully disable early data for people without full control of DC's network equipment. I don't know why Cloudflare made a decision about using headers and Too Early response. They have full control of their POPs. It will be better to measure RTT and use UDP based KV storage with tickets only for clients with high RTT. So for clients with RTT higher then access to KV storage it will be better to issue tickets, for other clients it will be better to drop early data and use full handshake. Currently, I'm working on a project with the same idea.