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.
{
            walletInstance->WalletLogPrintf("Performing wallet upgrade to %i\n", FEATURE_LATEST);
            nMaxVersion = FEATURE_LATEST;
            walletInstance->SetMinVersion(FEATURE_LATEST); 
        }
        else
            walletInstance->WalletLogPrintf("Allowing wallet upgrade up to %i\n", nMaxVersion);
        if (nMaxVersion < walletInstance->GetVersion())
        {
            chain.initError(_("Cannot downgrade wallet"));
            return nullptr;
        }
        walletInstance->SetMaxVersion(nMaxVersion);
    }
    
    if (gArgs.GetBoolArg("-upgradewallet", false)) {
        LOCK(walletInstance->cs_wallet);
        
        int max_version = walletInstance->GetVersion();
        if (!walletInstance->CanSupportFeature(FEATURE_HD_SPLIT) && max_version >= FEATURE_HD_SPLIT && max_version < FEATURE_PRE_SPLIT_KEYPOOL) {
            chain.initError(_("Cannot upgrade a non HD split wallet without upgrading to support pre split keypool. Please use -upgradewallet=169900 or -upgradewallet with no version specified."));
            return nullptr;
        }
        bool hd_upgrade = false;
        bool split_upgrade = false;
        if (walletInstance->CanSupportFeature(FEATURE_HD) && !walletInstance->IsHDEnabled()) {
            walletInstance->WalletLogPrintf("Upgrading wallet to HD\n");
            walletInstance->SetMinVersion(FEATURE_HD);
            
            CPubKey masterPubKey = walletInstance->GenerateNewSeed();