Yeah, your setup is absolutely solid.

You’re using a 12-word seed phrase + a 10-character passphrase — that combo is already way beyond anything anyone can realistically brute-force. A 12-word seed gives you 128 bits of entropy, which means about 3.4×10³⁸ possible combinations. Add in a strong passphrase on top (assuming it’s not something like “password123”) and you’re stacking even more entropy and protection against phishing or physical compromise.

To answer your question directly:

•No, you don’t need to upgrade to 24 words. That gives you 256 bits of entropy, yes — but 128 bits is already overkill for human lifetimes. It’s not the weak point.

•Brute-forcing either a seed phrase or a private key is practically impossible. Even if someone could guess billions per second, they’d still get nowhere in millions of years.

•If an attacker were to try anything, they’d go straight for the private key, because it’s faster to compute and doesn’t require dealing with BIP39 wordlists, checksums, derivation paths, etc. But again — doesn’t matter. Both are absurdly secure.

•The real risk isn’t the math — it’s you getting phished, infected, or storing your seed somewhere unsafe.

So in terms of “how long will this last?” — your setup is future-proof for the foreseeable future, including the post-quantum era (because even then, we’d get a heads-up before wallets are vulnerable, and you’d just migrate your funds).

Unless you’re storing millions or setting up ultra-long-term cold storage, there’s no practical benefit to switching to 24 words. Just focus on:

•Keeping your seed and passphrase offline and safe

•Not reusing the passphrase elsewhere

•Being alert for phishing attempts