George & Starbuck - -
Actually, I think it solved itself. In post #5 above, was trying to figure out if the RSIC would push the hat channel out far enough to hang the bolts down off, and not have the strut cross the channel. I was close, within a 1/16th.
Then I went out of town for business, and my carpenter forgot about RSIC and attached strapping to all the joists. The plan now is to attach strut to the joist (removing the strapping on the affected area), and then in the other spots attach the clips to the strapping. The strapping will give me plenty of clearance. Then put the lag bolts on, attach the sheetrock (2x + GG) with the bolts hanging through just like Curtis did.
Just need to buy the strut now, and cut it to size. My wife bought me a sawzall for christmas. Good times. Coming soon.
The L bracket would have worked though, or the plywood although I wasn't sure if that would have affected the height..