Perhaps it might work? You may have to be rooted on Android for your phone to be the tag to then make purchases. But being rooted and banking apps often don’t play nicely together, so you won’t be able to access your banking app on the phone if that’s something you’ll want to do alongside this.

If you want to go the route of just being able to backup and then copy it to a blank tag, I bought some off Amazon. They have cards the size of a credit card and also little circles too. But these seem to be permanent, like you write once to it and that’s it. There’s also a storage limit on them, so in the case of the Amiibo, I couldn’t scan them to the credit card sized ones because they weren’t large enough to store Amiibo data. You can also buy devices that will be the tag and cycle through like the Flipper Zero does but just for this purpose. Most of these seem to be for people like me doing it for Amiibo so no idea if it would work on this.

Which this now makes me remember something slightly unrelated I saw on Instagram…some people have taken the chip off of their cards and then put them in things like one guy cut the chip off and then submerged it into resin and made a ring which he could then scan at the Google Pay registers. Biggest issue I see with this is (besides the amount of time and work) that the card has an expiration date, so will inevitably useless after some time lol. But a neat idea, nonetheless.