actually it is a benefit to de-ice remotely rather than on the stand. Depending on the type of de-icing agent used you have around 30 minutes from deicing to take off, if you miss this window even by a few minutes and even if you are #1 for take off, its back to the stand for de-icing and again the whole procedure starts again.
Remote de-icing central to runway is the most benficial due to the fact that if there are delays or unusually long queues and you have to de-ice you dont have to go back to the stand ( and remember that there may be no stands available, as the stand you just vacated most likely would have been filled).
One thing to bear in mind with T5. You either have a very short taxi or a very long taxi (which could use up most of your 30 minute window) depending on which runway is in use for departures.