Thanks so much for the post – super helpful!
I’ll have to look into the wp_calculate_image_sizes a little more, but it looks like I’ll most likely add this into the next version of GP (with the 1150px taking the value from the Customizer).
I wonder what the best solution for the columns thing would be. I could probably write some code that detects the columns and the container width, does some math and then use the filter above to adjust the sizes?
Alternatively, you can use the Blog add-on to set the post image width and height to something much smaller (Customize > Blog > Post Image).
Thanks again 🙂