[flohofwoe]

Manual save-points are still useful though if you want to go back to a previous version and branch off a different experiment.

Pretty much the same how (mostly PC-) games combine auto-save, manual quick-save and manual 'explicit' save (with a name chosen by the user), and where the last N auto- and quick-saves are preserved (where N is usually a fairly small number). It's less about not losing progress (for that, having only auto-save is fine), but being able to go back to a previous 'checkpoint' and branching off a new timeline.