I split your comment into a new thread - please don’t post on years-old threads!
Most plugins are developed and maintained by third-party developers, not by the Caddy team itself. Since v2 is still in beta (but very very close to release candidates!) there’s not many plugins yet.
v1 plugins are not compatible with v2, so they’ll need to be reimplemented to work with v2. If you’re interested in porting the plugins yourself, then check out the docs here: Extending Caddy — Caddy Documentation