Bip39 Checksum Default range of iterations used in wallets is 2048. Rising this selection must help it become safer against brute force attacks, on the other hand you will have to shop this worth. To entry your wallet with tailor made PBKDF2 you need to use this script (or equivalent) https://socials360.com/story8845987/bip39-bitcoin-core-examine-this-report-on-bip39-phrase