Bip39 backup https://giphy.com/channel/ebliciwsah While it takes advantage of BIP32 process you'll be able to continue to import BIP39 seeds into Electrum wallet. Also other than BIp32 there is BIP44 Model which some wallet use to the technology of seeds. Exactly how much safety does a passphrase add? A BIP39 passphrase https://bookmarksbay.com/story20710186/bip39-light-the-greatest-guide-to-bip39-https-t-me-bip39-chat