I know ATC will write 'Good, Excellent, Satisfactory, Poor' on the sheet
Then you must be using out of date paperwork. That requirement was removed from the form around 5 years ago. The form originally invited an assessment of the student's "airmanship" (not RT) but as the person signing probably has no relevant qualifications to make such a judgment, the requirement was removed. AOPA produced an amended Qualifying Cross Country form.
Ideally you should have completed your RT practical exam before conducting any solo navigation exercises.