Ah, that makes sense. In fact I was not sure why replies try to say about the offline usability of certificates as I just used a SK approach as another example

Ah, that makes sense. In fact I was not sure why replies try to say about the offline usability of certificates as I just used a SK approach as another example of inefficient QR code uses. I don't think the SK approach is better than others or vice versa as long as proper fallbacks are provided and it seems it's the case for either NSW, SK or EU anyway.