The only thing I noticed that was a bit weird while building my rig was the amount of cable bar ends require. I already have a 46cm wide bar and the frame in road bike terms is probably a size 63cm or 64cm (25 inch frame)
So a pretty long frame with a wide bar and 120mm stem and internal routing (which should make the distance for the cable shorter...) created a situation where a 2100mm cable almost wasn't enough. I didn't need to clip the cable after installation and ended up with maybe 5cm extra cable at the end.