So if the visible barcode is consistent with the Q-tag, no problem? I have them attached to my bags and QF checkin agents IME treat them with disdain and attach paper barcodes anyway. It’s mostly worked.
I would suggest there are some who leave them in place as some type of "I've been everywhere badge".
Guilty, I can’t be bothered removing “security checked” stickers and they help me recognise my bag. I’ve been everywhere, man, I’ve been to HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG, HKG and HKG.