Flew this weekend and saw the Pre-check on my boarding pass. So, got interested.

At Sanford, there was a (new?) Pre-check lane in the west terminal, upstairs. There was only one person in front of us. Went fast and just a magnetometer.

At the out-station, the TSA guy gave us a yellow card, which allowed us to go thru just the magnetometer there, too. Again, faster than the full naked scanner. Shoes on and computers in case. No separate line, tho.

I have never put a KTN in, nor do I think there WAS a place to put it in on the booking form. I think since we paid for more legroom or because we were in Exit row seats, that we were given Pre-check.