Topic? What topic? We don't need no steenkeen topic here, man!
On the TRS end I used Red for Right (well... duh! ;-), Blue for Left, and twisted Clear and Black together for Ground. Above the split (I use amp as Bottom, cans as Top in my descriptions) I have Red and Black going Right, Blue and Clear going Left. So, no extra conductors above the split, just positive and negative, signal and ground, whatever the proper terms are. Red and Blue get fed through the center of the SMC connectors to the pins, and the grounds from the TRS (Clear and Black) get soldered to the knurled posts on the SMCs.
Here are some pix to help illustrate:
I meant that the W2799 has four conductors such that two are not needed for the legs above the split. I wanted to know what you did with those wires, Probably not connected.