Well, I use Arch Linux and the caddy package from pacman just works. You may checkout https://github.com/caddyserver/xcaddy for custom caddy build.

Besides, I don't use wildcard certs. I use caddy to reverse proxy a number of self-hosting things, and manually assign domain names to each of them. Caddy can handles many certs just fine.

I plan to make use of a Caddy on a cheap VPS to expose some self-hosted services behind Tailscale, behind Caddy will be a mix of Raspberry Pi and a occasional hosted VPS when trying things out.

How's your experience with Caddy regarding memory usage? I am currently serving a static site with 500 MB, but this is with very low to zero traffic.

I see 3-4% of 1GB ram usage for caddy only. Note that in my case caddy serves as reverse proxy and there is also very little traffic.