Actually I see that you are right about the 360px but this is not good. The setting for this needs to be higher than 360px but it needs to be set to anything less than 414px (iPhone 6+) maybe even higher than that. I would personally prefer it be 1 column on anything less than 768px. It looks silly two column when I’m previewing responsive screen sizes in my browsers developer tools for iPhone 6s, 6+ etc. So the question above remains… how and/or where can this be changed?