One sort of issue is that this only directly supports documents/DAGs, so representing many-to-many relationships is a bit iffy. This is similar to how Rust can'

One sort of issue is that this only directly supports documents/DAGs, so representing many-to-many relationships is a bit iffy. This is similar to how Rust can't directly represent cyclic data structures. It's not a huge deal, because working with indices works well enough, but it is a bit annoying.