As many of us know by experience, forgetting to save the project regularly while engaged in doing extensive edits can result in a sudden crash and loss of data. Normally I remember to do this and whenever I am doing serious mouse edits, my left hand hovers near the keyboard, poised ready to hit Ctrl-S.
But occasionally I get wrapped up in what I am doing and forget about saving. It would be useful if there was some built-in flag/indicator to alert me whenever I've made a lot of changes without saving. Maybe a counter that increments after each edit and gradually gets brighter or changes colour as the value increases would be a good feature to include on the toolbar.