Encountered this on AMS > OSL route 23 April. Never heard of it before and hope to never hear of it again. The plane was only ~40% full and it was still a shambolic experience with the KLM ground staff [~ 8 of them at the gate] apparently not understanding how it worked either. I asked in front of 3 staff if now that I had scanned my boarding pass and got my number for boarding if I needed to show my boarding pass again and was told that I did not. So when I just handed in my number at the gate I got yelled at and chased down the ramp because they needed to see my boarding pass again!! Last laugh was when the pilot announced we where already to go but had to wait whilst the gate staff checked the boarding list!! I also wonder what will happen with a full flight and the last to board will find no space in the overhead bins. No doubt more time will be lost while the attendants struggle with bags that have to be put in the hold! My guess is that this “smart” boarding [KLM’s words, not mine] falls into the category of a bright idea that has not been properly thought through. To me and all the other passengers I spoke with it just added yet another layer of stress to boarding!!