Moodle quiz competency based grading

We have a teacher who has created a quiz and doesn't want to score each question or get the overall grade in a numeric format. The teacher reads the essay question responses and decide if the assessment should be marked CA/NYC etc.

You may initially think, well 100/100 = CA, that's true, but has multiple issues. If the result is 78/100 then it gets complicated as to wether that equates to a CA or not. Individual responses would need to be assessed. Also the when the Student logs in and sees the grade 78/100, they aren't aware of what that means. Do they need to do more work etc, so by showing competency grading would match other assignments in Moodle.

While competency grading is available for document uploads, it should be available to the quiz as well.