Not sure if the Grid is flexible enough to, but I think it would be a nice feature to be able to drag and drop items into Collections instead of clicking the item, clicking the dropdown, then click add to collection. It would reduce mouse clicks and I think it would be something flashy to show in a demo.
We added this as a future consideration as we need to explore drag and drop functionality at a higher level as there are multiple places where it would be used. The scenario you identified is definitely one of these use cases