Students in my courses earn academic grades. They can earn an A, B, C, D, or F. I don't add the "chromatic variants" of + or -.
In my district, chromatic variants make no difference in the calculation of a students grade point average (GPA). A grade of B+ has the same value as a B-. So I don't bubble the chromatic variants. Many teachers throughout the district do.
I was never able to figure out why.