As part of staging deployment, we uncovered a spec bug: How do you combine two parameters (i.e. accounturi and validationmethods) in a single CAA record? Are they separate by semicolons? Unfortunately RFC 6844 is ambiguous on this topic, though RFC 6844bis (a draft) fixes it by clearly specifying semicolons. We’ve started a thread to discuss: https://mailarchive.ietf.org/arch/msg/acme/7Wuzl7-fqbMR_04jQNawQqEF17E.
We’re currently blocked on moving this thread to production based on the outcome of that conversation. We don’t want to deploy something to production that may cause interoperability issues, so we want to ensure we’ve accurately characterized any potential issues before we proceed.