Yes. I guess there are other use cases where subpaths will be backproped through multiple times, and it will be great if we can keep the graph and don’t have to reconstruct the whole graph with every backward call. This deviates a little from my original question but if we allow the graph to persist and grow then it can come to a point that forgetting some history, possibly by allowing deleting variables and reassigning leaf variables, becomes necessary and thus the question I was asking.