It should be said it is for technical but non-programmer users, "power users".

I don't think it is more scary than dconf-editor or regedit :D.

After this foundation is laid, there's no reason we can't add more "tutorial/wizard" flows, just as Microsoft kept revamping the Windows "control panel" but kept the old version.

What we can't do is simply drop config options like Apple. The Nix ecosystem aspires to be all mechanism minimal policy. If upstream exposes the knob, we ought to somehow expose it, at least via a free-form textual "extraConfig".