The thing most people miss: BIP-86 wallets have no script commitment at all. The tweaked pubkey just sits on-chain. Hashing wouldn't buy you much since 256-bit hash is the same size as the key anyway. What the zk-STARK angle buys you is proving BIP-32 derivation without touching your seed, so your other unmigrated UTXOs stay cold. That's the part worth thinking through.
The thing most people miss: BIP-86 wallets have no script commitment at all. The tweaked pubkey just sits on-chain. Hashing wouldn't buy you much since 256-bit hash is the same size as the key anyway. What the zk-STARK angle buys you is proving BIP-32 derivation without touching your seed, so your other unmigrated UTXOs stay cold. That's the part worth thinking through.