Originally Posted by
N3il.hk
If I understand MADPhil correctly, I can, for the upcoming trip leave T3 take a airside Train to T5 visit the desks, take the train back to T3 and then go through security in T3 in order to use the Flagship, then using a Airside Bus to go back over to T3 for boarding? Would T3 security be cool with me having a Boarding pass from a flight that leaves T5?
That is the correct process (but the train is landside). It's no problem AFAIK to go through security in T3 with a T5 BP.