I tried this yesterday and it didn't work for me. I used the CryptoQR to scan the QR code at check out, but instead of opening my Lightning wallet after scanning the code, the payment immediately went off my Google Wallet linked FNB card.
As there is no setting available to configure this it is not possible to have GPay/Google Wallet with your bank card as default contactless payment method if you plan to use this CryptoQR to pay with Bitcoin. You need to disable your Google Wallet payment method first.