Hi Ethan. My intuition and my knowledge are having a dispute that I believe only you can settle.
While I understand, very clearly, that when one is placing 705-FRK ON a wall or ceiling, the facing MUST be toward the room because if it's against the wall, it might as well not be there.
That said (here's where I'm not understanding), if 705-FRK panels are straddling a corner so both sides are freely vibrating, if the facing were AWAY from the room wouldn't it act as a broader-band absorber? Highs and mids being absorbed first, and larger wavelengths that makes it through the 2 inches of fiberglass would cause the facing to vibrate in sympathy and the fiberglass it's attached to dissipate the sonic energy as heat?
This seems intuitive, to me, but it seems you've always said facing should be out, no matter what.
Worst case, I'm just wrong.