1. I was only refering your suggestion to the op that both regs should be in "same orientation" as the left post as shown on the picture.The configuration I describe is just the typical twinset config with an extra transmitter. Why would I change which side I put my proper SPG? Using two DS4s with the HP from the right post would surely lead to an HP hose pointing up unless the DS4 was rotated?
To be clear I am describing left and right from the point of view of the person wearing the set.
My view is that the AI is just a nice to have and doesn't justify to much messing with an already working setup.
2. It has nothing to do with your own rigging.
3. There is only one meaning for left or right post for BM twin set. It is from the point of view of the diver wearing the set unless specify.