I use the manual release function on assessments so that I can go in and review the auto-grading by Matrix and adjust points as I see fit. Then, release the scores to students. 

BUT, some students take their exams months apart...

So, if I go in and grade a student's exam. Then, went to assessments and pressed the manual release button so they could get their score.

Now, if another student completes the same exam, their score will be released instantly.