When debugging responsive layouts, I find that most of my problems stem from parent or child objects that have unhelpful settings. Those settings break other related objects and the layout doesn’t function as I intended.
Solving this is fairly trial and error. I typically spend a lot of time going up and down the elements tree. While the individual elements are displayed (sort of) in the responsive view, the elements tree is not. That means I have to rely on my memory and naming conventions to know which object is a parent or child of another. It’s pretty painful on a complex page.
It would be super helpful to have the elements tree displayed in the responsive editor view so you could see the element hierarchy as you work.