@Moskito The default option is more than adequate.
Nobody can reverse-engineer an Argon2id hash to determine what the master password is.
However, if someone had an inkling what your master password might be, they could apply the Argon2id to their guess, and then check if the calculated hash matches the Argon2id hash that’s stored with your vault — if the two hashes are identical, then that attacker would have confirmation that the guess they made was actually the correct master password. Using a GPU and parallel processing, it takes less than a millisecond to verify an Argon2id hash, so an attacker could actually test thousands of password guesses each second (or millions of guesses an hour).
Therefore, if you have a weak password (something that could be guessed after a few billion attempts), then a hacker could find your master password by systematically testing different possibilities until they get a match in the Argon2id hash result. For example, if you use an all-lowercase password that contains 6 letters (or less), an attacker could easily reconstruct your password in an afternoon’s worth of work.
The bottom line is that having an unguessable master password is much more important than using Argon2id for your vault KDF. To secure your vault, you should use a randomly generated 4-word passphrase. This ensures that the number of guesses that would have to be tested will number in the quadrillions, requiring millions of hours to complete the Argon2id calculations for every possible word permutation.