It sounds good, but the examples are not responsive on mobile ... they don't stack as mentioned in the post but instead shrink. Eg: https://s.codepen.io/adam-lynch/debug/XwKWdG
I’d say it’s all working as described and intended: the examples are all simplified examples demonstrating particular aspects of the solution, and none of those examples are of the stacking business.
The draggable columns are a nice feature though.