Performing the following (note the range of 10,000):

`importmulti '[{"desc": "sh(wpkh([aeee1e6a/49h/1h/0h]tpubDC5bVdaveQYxGFztMShFAjU637kKjrs9FD8ne1oHR7z8tLeQJExsaxWRVeSpcCcYMdp5ecf2LQhuVaeYFZ7YEpvWTJr4nDGUJrmuvLuTSsp/1/*))", "keypool": true, "timestamp": "now", "watchonly": true, "internal": true, "range": {"end": 1000}}]' '{"rescan": false}'`

takes many minutes. @achow101 reports a similar import taking 6 minutes on his machine.
{
    Balance ret;
    {
        auto locked_chain = chain().lock();
        LOCK(cs_wallet);
        for (const auto& entry : mapWallet)
        {
            const CWalletTx& wtx = entry.second;
            const bool is_trusted{wtx.IsTrusted(*locked_chain)};
            const int tx_depth{wtx.GetDepthInMainChain(*locked_chain)};
            const CAmount tx_credit_mine{wtx.GetAvailableCredit(*locked_chain,  true, ISMINE_SPENDABLE)};
            const CAmount tx_credit_watchonly{wtx.GetAvailableCredit(*locked_chain,  true, ISMINE_WATCH_ONLY)};
            if (is_trusted && tx_depth >= min_depth) {
                ret.m_mine_trusted += tx_credit_mine;
                ret.m_watchonly_trusted += tx_credit_watchonly;
            }
            if (!is_trusted && tx_depth == 0 && wtx.InMempool()) {
                ret.m_mine_untrusted_pending += tx_credit_mine;
                ret.m_watchonly_untrusted_pending += tx_credit_watchonly;
            }
            ret.m_mine_immature += wtx.GetImmatureCredit(*locked_chain);
            ret.m_watchonly_immature += wtx.GetImmatureWatchOnlyCredit(*locked_chain);
        }
    }
    return ret;
}
CAmount CWallet::GetAvailableBalance(const CCoinControl* coinControl) const