Thanks for the explanation. I would instead just set the key to `null` or `undefined`. Makes it clear it's been consumed.

You can leave `stopPropagation` if you are so inclined, but please add a code comment where it's defined and list exactly what you have above. As you know `stopPropagation` is usually used in to stop an event propagation within a single event loop, not across 3 separate event loops, so its usage here is a bit confusion.