Yes, it can't do any harm, if the wiring from the battery is nice and thick. I'd recommend at least 4mm wires for the wiring from the battery to the relay switch terminals (30 and 87) and then on to the headlamp plugs, preferably 5 or 6mm for the lowest voltage drop. That's the diameter of the wires, including insulation. But if you order it and install it, you can always see how it goes.

Connect a voltmeter, or a multimeter on a DC volts range, up to the headlight connector earth and active pins, start the motor (to avoid flattening the battery), switch the headlights on, leave for maybe a minute or two until they stabilise their temperature, then measure the voltage at the headlight connections. Then remove the multimeter, and with the headlights still on, measure the battery voltage at the battery, and compare the headlight voltage with the battery voltage. If the difference is one volt or more, then the headlight wiring is too thin. If it's lower than 1 volt - preferably 0.5V or less, then it's OK. Even a 1 volt drop is far better than the standard headlight wiring (more than twice as good, actually!), so should make a worthwhile difference.