I don’t think I’ve done that before, but I saw this tutorial after doing a quick search – https://wpsites.net/web-design/make-a-gridcolumn-styled-blog-page-in-genesis/
For the blank Blog page, set your Homepage Displays to a Static Page, and then set your Posts page to the page you want your Blog Posts to appear. As you already know, once you add homepage widgets, the front page template will automatically show up as the home page. This is the way it’s going to be from now on due to the new Genesis 3.0/WP.
A lot has changed since the new Genesis 3.0 has been released, so there will be more updates to this theme (and others) to make sure everything is up to date and working perfectly.