Grader report will only show total points for Category and Course Totals when editing is turned on. If category editing has been disabled, the grader report should respect the display preferences for the gradebook in the category and course total columns.
In gradebook administration settings, disable editing of category and course totals.
Set gradebook to Natural Aggregation.
Set gradebook to display Percentage.
Turn editing on.
Category and Course totals columns show total points and not percentages.