Being able to backup/restore our key in human readable way is important for me. It is better to write down a word list than an scrumbled hexadecimal string...
For my keys, I like to use diceware as salt/pepper #duniterpy (base58) key generator. Converted it in base64 to be used in SSB.

@andrestaltz
How diceware differ from BIP39 mnemonic? Do you think manyverse can generate french words?