When I last flew out of E in September, I asked the TDC about signage. He said it was there, so I asked where. There was one sign that was turned around so that no passengers could see it. When I pointed that out, he went over and turned it around, but then only the people in a non-MMW lane could see it (it looked like the one with the four pictures). When I pointed that out, he said that there was other signage near the MMW, but when I asked him to show me where, he demurred and went back to ID checking.

That was the only sign, people in the line couldn't see it and I didn't see any language about opting out. Not an informed choice in the least.