Curious how you plan to handle Redstone and hostile mobs.
1. An optimistic execution strategy (the servers can run their own redstone)
2. A locking system allowing only one server to have redstone current in a given chunk at once.
3. A rollback-based system to repair race conditions caused by (1)'s optimism.
Hostile mobs are ALSO still WIP and:
1. Are only synced if two players are near each-other on two different servers.
2. Have their aggression entirely managed by a WorldQL script which sends messages to the appropriate servers instructing them to call LivingEntity.setTarget on the correct player.
Was hoping nail those both down before I shared it here, so please forgive me! Thanks for your interest and stay tuned.
Perhaps two chunks/servers could communicate fast and precise enough for redstone.
But Imagine the corner of a chunk receiving updates from two different servers.