4th was easier, and after a day of riding I’ve taken the time to unfuck the brakes this morning (they worked, but not well). Cantilever with quick links, the rear brake cable passed through the cargo rack bracket at an angle and rubbed on both sides, and the front was so squishy it was softer than the rear, in part because the clip to the quicklink was sliding loose on the main cable. Swapped the shorter front quicklink to the rear to get the junction below the cargo rack bracket, and readjusted the front to take up slack and work with the longer quick link.