Ah, gotcha. The question you need to ask is how early you want to get there.
If you are taking the Skyliner, you want to show up early at the Pop/AoA station. Everyone will have differing opinions, but I'd say the earlier the better. Perhaps 60 minutes before the planned start of the Skyliner (which itself is at least 1 hour before opening). The reason for this is that you will need to join the line at CBR for DHS. From what I read, they will take groups from the front of the Pop/AoA line and add them to the front of the queue to DHS, along with those at the front of the line of those staying at CBR. So, sorta like a zipper, one group from AoA/Pop, one group from CBR. It's not exactly like that, but close.
However, at some point, the CMs stop doing this and send everyone coming off the AoA/Pop line and sends them to the end of the CBR line. If it were me, I'd want to make sure I was in those first groups out of Pop/AoA to the hub to make sure I wouldn't have to go to the end of the CBR line.
I think even if you do get sent to the end of the CBR queue, you’ll still be to DHS prior to opening and prior to the general public, you just won’t be at the very front of the line to get into DHS or the point where they hold you after you tap in.