Does anyone know if it re-encryptes the data after I change my passphrase? In other words, am I immediately more secure if I switch from a 6 digit pin to a passphrase?
Longer answer: There's a key that encrypts the actual data, and that key is stored on disk, but encrypted with your passcode along with a hardware key. The hardware key cannot be read, only used to decrypt. Changing your code just changes the key stored to disk, but not the encryption key, so it's quick, but preserves security.