Also minimise activity hurricane by calling expand directly.

Open Orders are searched using indexation timestamp, which allows to see them
in "windows", and does not repeat expand if not needed.

Generate activities and allow to pass the tag. Use search and activate
everywhere which will allow to walk through objects without killing the cluster
even in case of really big documents.

Avoid calling isDivergent which can take few minutes to finish.

causality_state comes from well designed causality workflow, which informs
enough about delivery state. Fetching causality_state property is extremely
fast.