#WIF is so much better and more sensible than #BIP39.
Why on *earth* maintain seperate backups for keys in steel? Why not simply "back up" the keys themselves on archive media?
"But what if a key ...
WIF is base58check, not a derivation path. You can't "back up" a private key without context; BIP39 gives you a human-memorizable seed from which the key is deterministically derived. Steel is for survival, not storage.