David. If I remember correctly I did try the "direct route" and use the shorter arm of the carb linkage. I think I didn't like the heavy action and odd throw length that resulted from the lack of mechanical advantage the short arm provided. The bell crank method will let you fine tune the throttle "feel" with the bell crank arm ratio to your requirement.
The other thing is the radius of the cable turns required to use the "direct route". It is pretty close to the minimum radius standard for the cable I used. The first turn out of the side pod isn't the problem. It's the turn at the top back towards the carb that is the sharpest. And there are two fairly tight turns using the direct route and one big arc at the rear of the motor using the long route.
As in Andy's example the pull at the throttle peddle on my car is direct. I would avoid putting a 180 degree turn there as has been done elsewhere. That's just one more friction generating turn that can be avoided.
The last thing was the spring. The long arm gives you the most return spring strength for a given spring and I like the idea of a direct 180 degree pull against the cable action. The mounting points on my intake also required the location of the bell crank mount and spring anchor. Yours may be different and should be taken into account in your solution.
Use a old cable or a length of extension cord to measure the radius of the turns, map your route, and length.
As I said, this system has worked very well for a long time for me. I am sure there are others that work equally well also. What ever you settle on, go for maximum reliability, component strength, and least possible cable friction. As you can see mine is all rod ends and steel bell crank construction.