Do they have to edit your domain into a connections file or some such

Pretty much. I don’t remember the exact details, but that’s close enough for the cat.

No, as in the person installing the app to use the service has to edit a config file.

Yes, I have no issue editing config files. I’m self-hosting, that’s the point. All the technical load should be on me. But my completely non-technical friends should not have to edit config files to be able to access my self-hosted services. Everything, for them, should be as simple as possible.

It can be self hosted, but to connect the clients to self-hosted servers you have to edit config files, so it’s a very user hostile solution.