For SoCal,
Ontario Intl services San Bernardino and Riverside Counties - the CC is located in Riverside.
LAX will service LA and Orange Counties - the CC is located in LA.
Orders will be separated at their respective Customer Centers.
In regards of FlightAware, view departures from Louisville Intl (I posted the link a few pages back) First, only flights marked UPSxxxx are UPS fleet. Second, find the flight destination that is closest to your location. Last, find the flight departure time of those specific flights that coincides with your departure scan via UPS tracking. Like I mentioned, they won't be exact but within a few minutes from each other (consider the time the plane taxis on the runway before taking off)