Fuel dump is a hold over from the old 3 and 4 engine jets and is really not required on ANY twin. Aircraft certification requires an aircraft to be able to land at MTOW with a touchdown vertical speed of 360 FPM and suffer no damage. INfact the overweight landing inspection with less than 360 fpm consists simply of a visual inspection of the tires. Go beyond 360 of course and it gets expensive.
At max landing weight the aircraft is certified for a 660 fpm impact with no damage (and let me tell you that is JARRING).
The reason fuel dump was on aircraft was for 3 and 4 engine aircraft to improve your position should you lose a second engine, and to guartantee performance (GO around etc....)
It is never necesary to dump fuel in a twin, and haveing made 3 VERY overweight landings in my career I can tell you that landing overweight is the easiest smoothest landing you will ever make, though you will use more brakes to slow down... (Compare that with landing near the BOW of the aircraft, ohmygod do those hurt)
Cheers
Wino