@Max Priazhevskii We've been using async_reference since the day after V28 came out. Just a heads up that it is important to not use dots in your collection names (like we had "products_1.0" as a collection name) and to use the actual collection name in the schema for defining the reference, and not an alias. But of those situations caused us different (but similar) failures when loading data or querying. You can see details of our issues here, and on previous post linked there.