Within the past week they've changed the way the lines funnel at STL at Terminal 1-A but there's still no way to reach the A gates without the possibility of getting pulled to the NoS.

The ID checkpoints are now after the queue ends. In other words there aren't two queues before/after ID check now.

When I went through on Friday around Noon-time, the far right metal detector lane was closed but so was the NoS.

So far I haven't had to "opt out" in STL because I've always been able to go through the FC lane or the NoS wasn't functional during non-peak travel times.