I originally thought it was the truck using engine braking/GPS since it always felt like “regen” braking, especially with how hilly ATL is. There is some documentation on this, so I believed it.
Turns out both rear calipers were fairly stuck. Freed everything up (pins, boots, cleaned/lubed), and the dragging is gone—and so is that “regen” feeling. The truck coasts so well now I have actually use the brakes more to stop
Crazy part is how consistent it was, had me convinced it was drivetrain related.