The 'torque' on the nut was 'increased' in an attempt to better clamp the wheel bearing assembly together tighter, to stop the bearing parts, as well as the drive flange, from 'rocking' on the shaft of the CV, to increase bearing life.
In most other FWD cars, the inner race of the bearing isn't small narrow things like the loose parts that are in a Mini hub, they are all mounted on (basically) a long one piece tube, so they don't rock like the Mini ones do. When cornering, the wheel bearing and drive flange kinda do like Motor Bikes,lean over, only ours lean out of the corner,,,
It's really not a brilliant design,,,,,,,
In short, the tighter, the better, but the earlier CVs were only 'rated' to take 150 ft/lb and a bit to find the next slot. Since going over to the latest CVs, I've been getting better wheel bearing life.