If this is a device as you say and we make the first transaction and the private keys are deleted and wiped, the device will become worthless? If yes, what's the point of calling it a physical coin If it's only possible to use it once.
This wipe out process was designed to make sure that the bitcoin in the private key was still there,(if it has been transfered, the device will indicate it by shown that i have no private key)
And i think the physical coin was used by transfer it, just like ordinary physical coin. Instead of transfer bitcoin in the private key, we just transfer the private key.
The purpose of physical coin was to promote the recognition and acceptance of bitcoin to public, who might be more familiar with physical coins.
After wipe out, maybe generating another private key and shown the new address? Which can make it re-mintable
