Bip39 Vs Electrum Default range of iterations used in wallets is 2048. Escalating this range should really ensure it is safer versus brute force attacks, even so you'll need to store this value. To accessibility your wallet with personalized PBKDF2 it is best to use this script (or similar) to https://bookmarklethq.com/story18515006/bip39-list-pdf-the-best-side-of-bip39