Some posts here mentioned that after they faxed their inquiries to CIS, they got RFE for their cases. My guess is that if you send inquiry to the director, the adjudicator(s) will be so pissed off and you will get RFE even your case should have been approved right away.
If I were the adjudicator and if someone complains me about my delay, I am certainly not going to admit I was lazy, not productive, not efficient, etc, but definitely to excuse myself by blaming that the case is too complicated. And to prove I am right, I will certainly issue an RFE, a long, long one!
What do you guys think about this guess?