Last I saw they were working on it, there was just a lot of questions about how to validate that control was properly at parent domain level and not just at the

Last I saw they were working on it, there was just a lot of questions about how to validate that control was properly at parent domain level and not just at the subdomain. They wanted to get whatever was needed fleshed out and part of the ACME protocol before doing anything so that it wouldn't just be some hack they added for let's encrypt on top of ACME.