Otherwise we'll have confused dependency graph builder, which wouldn't be able to build proper graph. Didn't find a way to avoid world copy here, we can probably escape with some shallow copy here, but that will currently complicate code a lot. Ideas to consider here: - Use shallow copy of existing world after new ID management API is in place. Downside would be thread safety, kind of nice to have everything local. - Switch depsgraph away from ID_TAG and do hash lookup or so. This will slow down depsgraph builder, but will make code more reliable.