The touchless Pre-check worked flawlessly a few weeks ago at PDX for both my wife and I so it will be a nice feature to have going forward from my home airport. I decided to try it out at checkpoint 5 in SEA this afternoon and it was a no-go when I stepped up to the camera. Despite having the correct touchless icon on my boarding pass the TSA agent said that I still needed to provide ID but there was no literally nobody in line so it didn't make much of a difference in this case but I'm glad it works so well at PDX.