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.
if (vstr.size() < 2)
                continue;
            CKey key = DecodeSecret(vstr[0]);
            if (key.IsValid()) {
                int64_t nTime = DecodeDumpTime(vstr[1]);
                std::string strLabel;
                bool fLabel = true;
                for (unsigned int nStr = 2; nStr < vstr.size(); nStr++) {
                    if (vstr[nStr].front() == '#')
                        break;
                    if (vstr[nStr] == "change=1")
                        fLabel = false;
                    if (vstr[nStr] == "reserve=1")
                        fLabel = false;
                    if (vstr[nStr].substr(0,6) == "label=") {
                        strLabel = DecodeDumpString(vstr[nStr].substr(6));
                        fLabel = true;
                    }
                }
                keys.push_back(std::make_tuple(key, nTime, fLabel, strLabel));
            } else if(IsHex(vstr[0])) {
                std::vector<unsigned char> vData(ParseHex(vstr[0]));
                CScript script = CScript(vData.begin(), vData.end());
                int64_t birth_time = DecodeDumpTime(vstr[1]);
                scripts.push_back(std::pair<CScript, int64_t>(script, birth_time));
            }
        }
        file.close();
        
        if (keys.size() > 0 && pwallet->IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {