Wrong routing for 7.1 Surround Rear output in Mac OS

We have developed a virtual core-audio device that supports a specific 7.1 configuration, L R C LFE Rls Rrs Ls Rs (7.1 Rear Surround, somewhat like MPEG 7.1 C).

However, VLC assumes that our device supports what Apple calls MPEG_7_1_A (7.1 Surround) layout, which is: L R C LFE Ls Rs Lc Rc

So, there's no mapping for Lc (Left Center) and Rc (Right center) in our case - these are totally different speaker positions (between Left and Center, and Right and Center respectively).

VLC tries to set this MPEG 7.1A layout, without even checking if this is compatible/supported. It gets an error from the OS, but the error is ignored, and so channels routings are wrong.