If you're migrating from rsCardputer, Cryptspeak finds and migrates any existing unencrypted identity, messages, contacts, and settings the first time you unlock it after flashing. You don't need to do anything else for that to happen.

Wipes the entire flash before writing the new firmware. This deletes everything currently stored on the device, whether that's an existing Cryptspeak identity, messages, contacts and settings, or rsCardputer's plaintext data if you were about to migrate. Leave it off to keep that data. Cannot be undone.