You could try to debug the permission issue… Like take a note of the current permissions, chmod the certificates to 666 and the parent directories to 777 and see if that works. Then progressively cut them down again and see when it fails. And/or give caddy all the group permissions ssl, acme, certwarden… and then check which one makes it fail or work.




HA isn’t the only option. I think there’s two other open source smarthome solutions out there(?) And you could probably do with just an MQTT broker and a Python script, or something like that…
But HA isn’t a bad choice. They’re doing a phenomenal job. And related projects like ESPHome make it really easy to integrate microcontrollers. And if you want to do more smarthome stuff, it has a plethora of features, integrations, an app…
Extra hardware isn’t absolutely necessary. I have one server at home which does NAS, and I use 4GB of it’s RAM to run a virtual machine with Home Assistant. That’s enough for it, including a bunch of Addons.