This shouldn’t be necessary, because the stream helpers can update items in-place based on the item ID.
You could use that to update the state of the single stream entry with a deletion_requested: true, causing the template for the item to re-render and a minimal diff be sent to the client.
In fact this pattern would allow multiple items to be in this pending state simultaneously.
This also reminds me that probably you wouldn’t want to accidently re-add items to a stream during that event handler, or perhaps think about what’s the desired behavior - see stream_insert update_only aka stream_update by SteffenDE · Pull Request #3573 · phoenixframework/phoenix_live_view · GitHub & https://elixirforum.com/t/add-stream-update-to-liveview-streams/68107
