The dropdown menu in your screenshot affects how the grade in the 'Grade' column of the report is displayed. Disabling the less relevant columns for your course can be done from the Gradebook > Course grade settings page. Here you can Hide / Show any columns you need.
It would be my preference to have the following columns available:
Grade, Feedback
And disabled:
Percentage
Weightings
Average
Letter grades
Contribution to course total
Range
You can differentiate the display option on the grade item, by setting the assignment itself to display Real (Percentage) and the bonus bit to Real.
That way, you can clean up your grade report area where the students get their required info and feedback.
Nice to know: the Feedback column automatically shows the Feedback text content from the graded Assignment submission, if you wrote feedback there.
It would be my preference to have the following columns available:
Grade, Feedback
And disabled:
Percentage
Weightings
Average
Letter grades
Contribution to course total
Range
You can differentiate the display option on the grade item, by setting the assignment itself to display Real (Percentage) and the bonus bit to Real.
That way, you can clean up your grade report area where the students get their required info and feedback.
Nice to know: the Feedback column automatically shows the Feedback text content from the graded Assignment submission, if you wrote feedback there.