Don’t have an exact answer, but late night everything gets consolidated to the main check point. Last redeye I did was a walk through at normal security. Didn’t even bother trying KCM.

AFAIK the north checkpoint (next to the north KCM) closes earlier. I always go to that one as the random results in a quick few steps to the head of the line.

The mid KCM (that dumps in next to Qdoba) almost isn’t worth trying as you usually walk past a check point getting there. Not a time saver with the inevitable random to then double back. In case it’s been awhile since you’ve been there, the south KCM is closed indefinitely.