Use case to fill would be: "I receive an NFT (a long time after his mint) and I really want to verify that I am the issuer".
This is not a realistic use case. If the policy ID listed when you query a Cardano wallet matches the string of a policy ID that you minted in the past, then it is verified. There's no way to send someone a token that has a policy ID without being signed by your skey, so there would be no possible way to spoof it, and therefore no need to 'verify' it using a key in the future.
EDIT: In re-reading your post, maybe I am misunderstanding.. Are you saying you'd prefer to not keep a record of the policy ID strings you've minted in the past? It seems like just creating a text file that stores all of your policy IDs would be the same effort as keeping the .vkey or .skey's from past policies..