Lead Developer
It’s the same issue as I stated above – the Page Builder has the same restrictions as GP because that’s just the way the CSS works with the images – no magic for it unfortunately.
Your best bet is to use a different image on mobile with an aspect ratio closer to what you’re working with using the CSS I provided above.
Documentation: http://docs.generatepress.com/
Adding CSS: http://docs.generatepress.com/article/adding-css/
Ongoing Development: https://generatepress.com/ongoing-development