> they only communicate when one node has exclusive ownership over a block another node needs to write to and it needs to communicate that he has exclusive own

> they only communicate when one node has exclusive ownership over a block another node needs to write to and it needs to communicate that he has exclusive ownership, and also after each writes you need to invalidate cached data on other nodes, and read new data from some transactionally consistent store, which will do all heavylifting (syncing/reconciling writes), which is kinda FDB.