@danstuff thanks for taking the time to share the photos.
I asked SBC to route the cables the same way and they did a great job. They said the BB area was "tight" so again, thanks for the advice to keep it 24mm Shimano.
They also used heatshrink tubing to keep the cables together.
Those show the routing. Di2 cables attach to brake hoses with heatshrink, all going to and from a 3 port Junction A box on a Fourier mount.