Any status for RFC 8657, ACME CAA support? This is for restricting which account and which validation methods may issue certificates. The CPS says they may use it, which is too vague and I'm not going to test it right now.
By the way, I appreciate the support for short-term certificates as well; Letsencrypt doesn't have it, though invalidation can be detected with OCSP or draft-aaron-acme-ari.