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 (!CanGetAddresses(internal)) {
        return false;
    }
    CKeyPool keypool;
    {
        LOCK(cs_wallet);
        int64_t nIndex;
        if (!ReserveKeyFromKeyPool(nIndex, keypool, internal) && !IsWalletFlagSet(WALLET_FLAG_DISABLE_PRIVATE_KEYS)) {
            if (IsLocked()) return false;
            WalletBatch batch(*database);
            result = GenerateNewKey(batch, internal);
            return true;
        }
        KeepKey(nIndex);
        result = keypool.vchPubKey;
    }
    return true;
}
static int64_t GetOldestKeyTimeInPool(const std::set<int64_t>& setKeyPool, WalletBatch& batch) {