The additional screening is at the boarding gate, just after you step off the escalator and onto the jetty. It’s a fairly quick affair, as others have said give your hand luggage to your other travelling parties. No extra time is required, as you have already passed through the gate. The G4S employees conducting this charade are rude, abrasive and rather enjoying their positions, examining your shoes, belts and duty free purchases. They were incredulous that I had no hand baggage, asking me several times how many bags I had and walking around my person to check I was telling the truth and hand snuck a bag in.