Exactly. The original problem was "people are losing all of their work cause they're not saving." So you autosave every minute or so to a separate "recovery" location, then if the user exits without manually saving, on next startup you give them the option to continue from the last autosave if that autosave is more recent and not identical to the last manual save. Doesn't require full change logging, and only requires one "last autosave" at any given time. IIRC this is how your Word example from the 90s worked.