@tialaramex I don’t know if there’s general work on CAA and the 10 Blessed Methods, but as it applies to ACME validation types, that’s actually part of the same draft as account key binding.
From the examples the appendix:
example.com. IN CAA 0 issue "example.net; account-uri=https://example.net/account/1234"
example.com. IN CAA 0 issue "example.net; acme-methods=dns-01,xyz-01"
At a glance i don’t see a Boulder bug open for it.