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.
{
    std::map<CTxDestination, CAmount> balances;
    {
        LOCK(cs_wallet);
        for (const auto& walletEntry : mapWallet)
        {
            const CWalletTx& wtx = walletEntry.second;
            if (!wtx.IsTrusted(locked_chain))
                continue;
            if (wtx.IsImmatureCoinBase(locked_chain))
                continue;
            int nDepth = wtx.GetDepthInMainChain(locked_chain);
            if (nDepth < (wtx.IsFromMe(ISMINE_ALL) ? 0 : 1))
                continue;
            for (unsigned int i = 0; i < wtx.tx->vout.size(); i++)
            {
                CTxDestination addr;
                if (!IsMine(wtx.tx->vout[i]))
                    continue;
                if(!ExtractDestination(wtx.tx->vout[i].scriptPubKey, addr))
                    continue;
                CAmount n = IsSpent(locked_chain, walletEntry.first, i) ? 0 : wtx.tx->vout[i].nValue;
                if (!balances.count(addr))
                    balances[addr] = 0;