My feeling on hangar steak is that because of how thin and tender it is, you can do a direct heat cook the entire time. It should take only 5 minutes or so to get to med-rare.
2013 Stumps Classic - Delivered 4/15/13
Large BGE - Rescued 2012
2010 WSM 22.5"
2010 Weber genesis gas grill
Rescued 22.5 Weber One-touch gold
BBQ Guru CyberQ
2011 Built UDS - Retired