I am a teacher and like to restrict to single user view when marking an assignment, so that I can select all, bulk add grades and feedback.

However, if you mark this way, it treats the grade as an override and the 'assignment need marking' notification doesn't update the notification - this is found in the activiites list in RHC under Activities (in GB view). Overridden grade won't show in assignment but shows in GB.

[ED:Maybe if you do overrides it maybe better to go back to original activity or notify user that the grade is being overridden and what this means.]