I think this is where it gets interesting. With partition dependency propagation, backfills are just “hey this range of partitions should exist”. Or, your “wants” partitions are probably still active, and you can just taint the existing partitions. This invalidates the existing partitions, so the wants trigger builds again, and existing consumers don’t see the tainted partitions as live. I think things actually get a lot simpler when you stop trying to reason about those data relationships manually!