Re: Commit progress listener
Interesting idea! From what I read about the EventStrategy, this is a feature stemming from TinkerPop and questions about it could best be addressed there.
Note however that gremlin OLTP traversals are executed mainly depth first, so any new events introduced would be rather be at the level of branching in the graph than at the level of traversal steps. Possibly, execution based events would only be useful after barrier steps, which break the depth-first pattern and therefore, passing such a barrier would give a sense of progress in the execution of a traversal.
Best wishes, Marc