I had a walk round most of the ground before the game and everything seemed calm and under control, contrary to my worst fears.
Got to K and was in very quickly (but I had a paper ticket as I knew that worked!) Heard various tales from people around me. Some got in with no issue using NFC, some didn't and needed the barcode and one person near me has 6 season tickets so the steward just let all of them in.
We will be asking the club for feedback of course but it certainly doesn't seem to have been the large scale disaster it could have been, so that's a huge relief.
All the complaints I've had were about the food and beverage service. The catering company appears to have completely underestimated the demand and been woefully underprepared, in terms of both stock and manpower.