Client authentication is rather complex mainly because there are so many variables depending on the use case. So be aware that it’s infeasible to have good coverage from examples.
Caddy can act as your own CA, and other Caddy instances (or any ACME client, really) can get certificates from it. Again there are a lot of variables here.
In short, Caddy on both the CA/server side and the client side can automate all of the certificates, but you will have to manually configure trust or distribute the trust into each device/system. And decide on various configuration parameters that you tune to your needs.
I think you forgot a link. Which page?
But I think they’re strictly examples, not significant domain labels.
To be honest I have not used any of them other than playing around to check them out; I think they are mostly vibe-coded, so if you’re cool with that you can try. Here’s one I saw recently that looks more polished: CaddyUI v2.4.3 — dashboard polish, smarter health dots, multi-host fixes
And yes, you can always manually view and manage the Caddy config by using Caddy’s config API: API — Caddy Documentation