I have not departed in the early morning since T2 opened, BUT I would say absolutely 100% yes....because:

Korean Air is of course a HUGE tenant at the airport. And in the morning, they had alllll of their American flights. At 4:30 PM for you, that's Southeast Asia departure time.

Even then, specifically at T2, there are four airlines operating.....BUT basically, Delta/KLM/Air France just have 1-2 flights a day each, so that whole terminal is for Korean Air. They have introduced self bag drop, more kiosks, etc., so I strongly believe you can breeze through check in in under 5 minutes. Also, if you do self bag drop and kiosk, you get expedited security clearance at the auto gates (that's what I see advertised at least).

T1, still, again, KE is gone. OZ is still big and every other airline is there, but again, all these smaller airlines are not the massive operation KE is. They took a giant chunk out of the reason for slow processing.