I agree, except with the non-concern of the SB cut out. I can't see it being that difficult in just downsizing the size of the cut out and making it the holder of the SB with a poly? bearing and closing off the bottom of that member with a structural cap.
That would also allow for an upgraded splined SB, especially nice if a straight one would miss the engine damper which is in that area I suspect. The unibody for track use can always be more robust IMO.
I thought there were new anti-dive considerations with this set-up to explain the control arm angles vs say a RMS set up. That is only a guess though.