I am in the same situation as you. I submitted two I-140s(EB1 & NIW) to NSC in this August. Two weeks ago I file I-485 based on my I-140 receipt of EB1, because I was more confident with EB1, although it's not so flexible as NIW. I heard that if necessary, I can later transfer I-485 to be with another I-140. I don't have a lawyer. You'd better consult with your lawyer.