A long ago feature of Moodle assignments has now returned! Instructors can now control when grades are released to students in a specific assignment.
If you need to go through a few rounds of grading in the same assignment you can edit the assignments settings to allow for multiple rounds, but the grade is not released to students until you are finished! Rather than multiple updates being sent to students as you go through your grading sessions.
While grading you can edit the “Marking workflow state” to what is appropriate for your action.