One legitime question, not trying to criticize. Why did you ask for internal routing frame if you where planning to use a standard / redshift stem?
I also have an internal routed titanium frame and I actually regret having made it internal, but I am not sure if routing it out at the bearing cups is the way to go, as more crap is likely entering the bearing areas through the cable openings, and you still get the harder maintenance of the bearings because of the cables goung through them