Bip39 Words. Thanks to the cryptographic style of BIP-39, a weak passphrase would not reduce the security of another wallets or help reveal the seed words. No, there is absolutely no technical limit towards the duration of the passphrase. On the other hand, with the sake of memorability and practicality, https://socialislife.com/story4635470/bip39-mnemonic-https-linktr-ee-bip39-bip39-words-fundamentals-explained