Jump leads for 4.4L V8 diesel?

[felixlg]

Bought a 2017 Range Rover with the 4.4L diesel V8 and, since it's a Range, thought it would be a good idea to buy some nice jump leads for it to keep in the boot.
Best ones I could find were 50mm2 cable, although the manufacturer only rates this for up to a 3L diesel engine.
Anyone know if those will be OK to use, or where I can find some better ones? I worry if the cable is much thicker they will become very heavy / inflexible / expensive.