This looks really nice. I was reading about this and realized it had similar ideas to this [1] Phd thesis from Jon Gjengset. I checked his twitter [2] and it was based on his work indeed.
Great that someone is productionalizing this!
Btw, is Jon involved in ReadySet?
[1] Partial State in Dataflow-Based Materialized Views - https://github.com/mit-pdos/noria