session.run

is actually the core API for kedro's pipeline now. The use case of debugging is a valid one, especially without the access of a debugger. The current concept of "free outputs" is essentially pipeline's output (node's output that has no consumer, thus intermediate output are not included) - set of catalog entries (anything defined in the catalog). From my experience, this is not convenient as the intermediate output could be useful for debugging, but I think the main reason is that kedro tries to be memory efficient. I think it's one area we could improve on interactive workflow.