I've never used the NSC ticket exchange because I hardly ever miss a home match, but do people not just hand over their smartcards? I didn't realise they actually went to the trouble of getting a paper ticket printed off. I'm not suggesting for a second you're wrong, I'm just surprised that's how it works.
when we have used it - we have met at the turnstiles, given them the smartcard to get through and taken it back straight away. No hassle.