The closest thing that I am able to do, is to make a quiz that does not count (in classic quizzes a practice quiz or in new quizzes in a group worth 0% of the final grade). I add extra questions to be randomly selected by the quiz, and set the quiz to unlimited attempts. Students can then repeat that quiz an unlimited number of times as practice, before submitting the graded quiz. Then the graded quiz can be muted for final grading, while the students can still review their practice attempts in the practice quiz.
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