A bit like how us old timers had to write our exams in the pen and paper days.

Is it? That's how I've always written them (and still do to this day). I write the first draft linearly from start to end, then go back and do my revising and editing.

Will Google Docs provide that level of detail for revision history in a way that teachers can easily see that's it's likely AI-generated, and have high confidence in that?