Oddbean new post about login | logout That's totally possible. Someone on here said their warning stickers stay up longer than the other stickers so that definitely points to them blending in.
It's a dual-edge situation: they do disguise better to ensure longevity, but that also might be a crux because they blend in so well it appears to just be an ordinary advisory sign. Perhaps a '₿' symbol could be added, or the QR label size increased? Additionally, if you're considering revamping an existing sticker, try replicating similar design aspects of the 'GOT INFLATION' one (repeat a successful action).