On small screens of course that wont work. On small screens that's why they don't have a charms bar. Or snap apps. Microsoft has been in software business more than me or you know about it. What can happen on small screen is tile can zoom in to on screen to over lay so that it takes up all or most part of screen, giving you a feel of full screen app. The way it does right now when you long press a tile. Only difference being it actually expands to take more screen space. The way cards pop up on iOS or Google Now.
I guess many people understood my post the wrong way. AGAIN I am not trying to advertise my concept design, nor I am suggesting that it's the best and the way it should be, it's not what this post is about, it's more about the chances that are available for Microsoft to seek, and how to execute them fast enough to get back into the game. It's about simplifying things for real this time, removing many of the limits that this beloved OS had, for it to grow properly.