That wouldn't work for caddy if you also follow the best practice to have a CAA record pointing to the issuer and account URL, unless caddy is also managing DNS records in addition to being an HTTP server. (I don't know if it is, but I would think it's a layering violation for an HTTP server to also be a DNS server.)
> (I don't know if it is, but I would think it's a layering violation for an HTTP server to also be a DNS server.)
Caddy 2 is, at its core, a server of servers. The HTTP server is just an "app module" for Caddy. There are other servers; I don't know of a DNS server app yet. (CoreDNS is a fork of Caddy v1, though.)