That anchor for the front brake is poorly designed (A). The most efficiant\ powerful anchor will be site B, through the unicrown, The hole the reflector is mounted in. This requires a piece of hardware bolted onto the front of the fork with the cable routed into it.
Doesn't look as clean, but way more stable\ powerful.

The one in the pic is better, i'm taking even more heavyduty.

U.S. Backstop V-Brake Housing Stop
Frame mounted clamp-on housing stop for linear pull brakes. Designed to replace cable guide or lack of cable stop on top tube. Machined and anodized 6061 aluminum, hinged for easy installation. 1 1/8, 1 1/4, 1 3/8, 1 1/2” – Black, Silver