Setup tool - confusing screen

This setup screen is confusing, especially for someone installing neos for the first time. It requires knowledge of how multiple packages, configuration and sites interact - while you e.g. only want to a) test the demo or b) start with a fresh, empty install.

A question that arises is: If I fill out the fields for a new site package, does the still selected site package at the top still get used? If not, why is it still active?
Do I even need to create a new site package with a dummy site?
And if I just want to try the demo, do I still have to specify a site name?

dummy package name: neos.stage
and site name:

… while having the Neos.Demo package at the top selected, results in an error page.

I created an issue from this at - thanks for bringing it up!