The likes if AMS have a lot more gates available and often each airline uses regular gates so it is a lot easier.

At LHR T5 if you ask at the lounge they can tell you what hate the expect the flight to go from as if is know a long time before but they can say it may be subject to change and is not confirmed until the inbound has often parked up. I believe the 60 / 45 rule is also a BAA thing to keep you in the central shopping area longer.