I just upgraded a server to Caddy 2 this past weekend. It's running a single WordPress site.
There were some gotchas in converting the Caddyfile to the new format, but I eventually sorted it out. Caddy 2's method of updating the config made the iteration process a lot faster.
I'll admit I got bit by a few differences between the v1 Caddyfile and the v2 Caddyfile too. Namely forgetting * at the end of a path _prefix_ matcher. (In Caddy 2, path matches are exact, unless you suffix with a *.)
There were some gotchas in converting the Caddyfile to the new format, but I eventually sorted it out. Caddy 2's method of updating the config made the iteration process a lot faster.