To the best of my understanding the ability to re-score miss-keyed responses is a feature request (https://ideas.digitaled.com/) and not part of the current release. Also, and this part is something I am not 100% sure of, if Student A attempted the original question they will see the original question in their gradebook. While if Student B attempted the "revised" question they will see the "revised" question in their gradebook. It would be far more confusing if everyone saw the revised question, even though half of them were graded with miss-keyed answer. To this end, I would recommend using the "edit question comment" field when manually correcting the miss-keyed student responses.
Suggestions for creating great content, from the experts.19
A place to share course modules, lessons and assignments or question banks.5
Quick Code Snippets
Short, reusable bits of code for use in algorithms and grading.40
Ideas for teaching with Maple T.A., and unique applications of questions and assignments.1