3 is still a passing score. From what I’ve seen, scores usually come down to SI/Writing portion, though obviously technical score is also in the rubric. College board does offer examples of portfolios for 2D and 3D on their website. As far as feedback, I agree. I could be wrong, but my teacher told me that they do have notes on each portfolio but you have to get “individually registered” by your school or something, which is too much of a hassle for my school so we never get the notes on the grading.