Don’t know who needs to hear this, but: To recover a k-of-n multisig wallet, you need k of the private keys AND n OF THE PUBLIC KEYS. Do yourself a favor and include a backup of the output script descriptor (or all public keys) with each private key backup.

Why? In multisig output types, the output script contains only a hash. The actual Redeem Script, Witness Script, or Leaf Script has to be revealed in the input or witness stack when spending. You need either the pubkeys or the descriptor to regenerate that script.

If you only have k private keys and k public keys left, you may a) not be able to tell which outputs are yours, or b) would be able to sign for the outputs, but cannot reconstruct the necessary input that allows you to do so.

I know this gets talked about a lot, but I just saw someone writing that they "have been learning about multisig for years" and just learned about this. So clearly we need to talk about it even more.