In this view the save action is more like a commit, where the user manually checkpoints and also offers a simple description of why this is an important point.

In this view the save action is more like a commit, where the user manually checkpoints and also offers a simple description of why this is an important point. But in my view all intermediary points also need to be saved, because the user might have forgotten to explicitly checkpoint, and might still want some undo/redo capability that is more granular than just checkpoints.