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 (database.IsDummy()) {
        return true;
    }
    BerkeleyEnvironment *env = database.env.get();
    const std::string& strFile = database.strFile;
    while (true) {
        {
            LOCK(cs_db);
            if (!env->mapFileUseCount.count(strFile) || env->mapFileUseCount[strFile] == 0) {
                
                env->CloseDb(strFile);
                env->CheckpointLSN(strFile);
                env->mapFileUseCount.erase(strFile);
                bool fSuccess = true;
                LogPrintf("BerkeleyBatch::Rewrite: Rewriting %s...\n", strFile);
                std::string strFileRes = strFile + ".rewrite";
                { 
                    BerkeleyBatch db(database, "r");
                    std::unique_ptr<Db> pdbCopy = MakeUnique<Db>(env->dbenv.get(), 0);
                    int ret = pdbCopy->open(nullptr,               
                                            strFileRes.c_str(), 
                                            "main",             
                                            DB_BTREE,