Bip39 buffer is not defined https://rylanmecp341.wpsuo.com/bip32-vs-bip39-which-is-better-for-your-copyright-demands Though it uses BIP32 approach you can still import BIP39 seeds into Electrum wallet. Also aside from BIp32 There's BIP44 Model which some wallet use with the era of seeds. Due to the cryptographic style of BIP-39, a weak passphrase won't lessen the security https://ok-social.com/story5525664/paper-wallet-bip39-the-greatest-guide-to-bip39-https-t-me-bip39-chat