Currently T4 is not at 100 or even 50% utilized. By then, expect crowds hanging around the gates standing as there's very limited seating around the gate. And expect delayed departure which will make things worst.

From what I observed, T4 design is for passengers to shop until time is close to departure before one heads to the gate and stand around the gate. One good thing for T4 is the smoking rooms. It's all A/C and unlike T1 where there's only one and it's outdoor which is heat and humid.