I can't find a demo on mediamath.com or http://strand.mediamath.com or even in the source tree.
I can kind of imagine from the example fragments how an editable grid might be
put together with mm-grid and mm-collection and mm-grid-item template but it sure
would be nice to see a complete working demo, as a whole html page showing all links
and styling and so on.
Also, with the size of mm plus polymer, it is extra important to not have full page refreshes,
so i'm wondering how you deal with routing and tabs and so on.