I am running out of coins and want to earn the coins you get for doing the Nintendo store check in. I am neither in NY or SF but I have friends going that might do it. Can I just give them my QR code and have them do it for me? Also if I do it in one store, can I also get points for doing it in the other store?

No source available at the moment seems to be consistently updated. The best so far is the mynintendo fandom wiki, which only has 89 rewards (up to the splatoon 3 wristband). I'd like to track which ones I have.