When the wallet is rescanned at startup in `bitcoind`, there seems to be no way to interrupt that in a clean way (other than forcefully killing the process).
{
    CTxDestination address;
    if (ExtractDestination(scriptPubKey, address) && !scriptPubKey.IsUnspendable()) {
        auto mi = mapAddressBook.find(address);
        if (mi != mapAddressBook.end()) {
            return mi->second.name;
        }
    }
    
    
    const static std::string DEFAULT_LABEL_NAME;
    return DEFAULT_LABEL_NAME;
}
/**
 * Mark old keypool keys as used,
 * and generate all new keys
 */
bool CWallet::NewKeyPool()