Is there science in the length of cantilever straddle cable?
Yes, and that science is called trigonometry. As withered preaches, changing the angles affects the mechanical advantage, and the rate of change of mechanical advantage through the stroke.
It’s called a cantilever brake for a reason. Maximum efficiency is reached when the straddle cable is at 90 degrees to the line from the brake pivot to the cable clamp/anchor
Is there science in the length of cantilever straddle cable?
As short as possible? A specific length? Follow manufacturer's advice written in the thrown away manual?
(Not my picture.)