To answer my own question, yes there is a fast track queue but last night everyone was in it There was only 1 queue open, the furthest to the right. Only about 15 people in front of me, but it still took 20 mins to process

My Air Malta flight landed a few mins early, I rushed to flight connections to find I was the only person on the bus to T3 - as soon as I got in, the driver drove off

After the personal transfer I arrived at T3 about 15 mins after leaving the plane in T4, but as I said the queue took ages so it was another 20 minutes or so before I was in T3 itself.

So I made the flight with plenty of time. 64K is a great seat and the flight seemed to be over so fast. Of course now its 3am in Singapore and I'm wide awake posting on Flyertalk