Bip39 Bitcoin Core Default amount of iterations Employed in wallets is 2048. Escalating this number should really ensure it is safer against brute power assaults, however you'll have to keep this benefit. To obtain your wallet with custom PBKDF2 you must use this script (or very similar) to work out https://wiishlist.com/story19322216/bip39-mnemonic-code-converter-tool-the-2-minute-rule-for-seed-phrase-generator