No problem with your figures and I agree that you will nearly always make fuel leading to the need to burn fuel at destination to get the landing weight down. However on restricted runways if the RLW/RTOW is lower than actual/calculated/maximum LW/TOW then it doesn't matter what gear you have you wil be limited to that weight.
Last summer Nex operated a leasd 146 with the beefed up gear (EICNQ) which it tended to operate on the longer routes. For the times when the wind was in the right direction and the temperature wasn't too high it made a big difference - but unfortunately those days were few and far between!