The really smart ones about this stuff work at Schiit and a few other places, the rest of us are just trying to follow along
My suspicion from what I read/heard the Schiit-brains say is that they are avoiding the complexity of delta-sigma DAC chips by doing much of the preprocessing with standard DSP parts, and then going into a relatively simple, possibly discrete, circuit. Now speaking completely out of my lane, maybe something along the lines of the PWM-AFIR designs I linked to a while ago, or something radically different?