I also see that Elementor has just published a child theme -- but the interesting thing is its a child of their page-builder, not of a theme.

https://github.com/pojome/elementor-hello-theme

The reason this is so interesting, is because (apart from the awesome control it gives us mere mortals), it means that with Elementor 2.0 you now don't need a theme, premium or otherwise. In fact, adding virtually any theme at all is just adding bloat!

I am using it for a new site now, and loving it!