That's a good point. I probably will add some sort of destroy method. I figure in most cases with delegation you are referencing an element that is not likely

That's a good point. I probably will add some sort of destroy method. I figure in most cases with delegation you are referencing an element that is not likely to be removed (such as document), but I probably should add a way to clean up stale objects. As for WeakMap, I wasn't even aware of that, looks awesome.