It would be very helpful to be able to simply select the users we want, and on the right hand side panel, where it says "enroll users" there should be an option to "edit enrollment" and we can then mark multiple users complete for multiple courses, at the same time. This would be useful for the purpose of historical completion records.
This feature is available in the Course Activity Report. While the report supports up to 30 courses, editing completion is limited to one course at a time. Despite the limitation, it is still a big timesaver.
We use this feature to "grant credit" for 13 courses for new employees who attend a two-hour onboarding session. The onboarding course is an ILC, which has a post-enrollment rule to create new enrollents in the 13 courses upon completion of the ILC.