Re "hand writing is harder to revise", I never had an issue with erasing words or parts of the text and using asterisks, end footnotes, the margins and whatever free space available (with arrows or not) to do revisions in written exams. Nobody complained and afaik it was fairly standard to do where I studied, as long as your exam itself was actually legible. Granted, I refer to math-related exams not essays on literature or philosophy where form may have mattered more. On the other hand, I cannot imagine writing any math during an exam on a computer.