Correct me if I'm wrong, but does Cloudflare still not have a "Create Account" button on the account listing page? I think you still have to sign up from scratch doing plus-code email tricks, then invite your original email address as an admin, juggling multiple accounts. They should consider fixing that first.
If I want to onboard a client to Cloudflare, I have to ask them to create an account and then invite me, which is a lot of friction for non-technical people.
A “create account” button accessible to me would be so much better. Then, I create the account and invite the client to join as owner.