I've done several ins and outs in the last few weeks, mostly not through fast track.
Queue lengths and waiting times seem massively better than last year when it could take up to 30 minutes to get through non-fast-track security and/or immigration. None of my transits this time took longer than 10 minutes.
It seems like there are lots more immigration desks and security channels rather than fewer travellers.
That's the way to do it!