So I was just under a balcony this week http://bt.etree.org/details.php?id=511102. In the end I ran to the top of the lip and it came out pretty good. Did I have the right idea, go up as high as you can and use the most directional mics you got? It seemed to effect the bass to my ears, if I walked out from under it, it the lows where clearer.
Did you roll off the low end?
I think you are right... as directional as you can, and as high as you can... to a point. I wouldn't want to get too close the the ceiling. In a tight spot maybe half way between head high and ceiling. I don't have any data to back that up, just a gut feeling that if you are inches from the ceiling you will have a lot of evil reflections which will show up as weird phasing. Similar to an umbrella.
middle point between floor and ceiling if you are close to the front of the overhang. i don't think directional mics are going to help you that much since you are already losing a lot of waveform. if you can walk up and hear the preshow pa music and compare it to your spot, and it's much worse... shut off your machine/s, pack up mics, micstand, roll up wires, and put all of that stuff in the coat-check. sit back and smoke pot... or whatever.
It worked out pretty well for me at the solid blues show, I am 6'5 so I could listen up and down and in this case way up was where it was at.