This is related to #14150 and possibly others, but it's actually a separate issue.

For instance, when using the following query:
`bitcoin-cli scantxoutset start '[{"desc":"wpkh(xpubABCDEF/0/*)", "range":100}]'`
I can get a list of UTXOs, but no way to get back the index which derived that particular UTXO. So it's not much better than deriving on the user side and specifying addresses one by one, so that I already have a cache of addresses to match.

Not sure what the solution looks like. One way is to repeat the full descriptor in the utxo. That might get verbose though.
"    \"scriptPubKey\" : \"script\",    (string) the script key\n"
            "    \"desc\" : \"descriptor\",        (string) A specialized descriptor for the matched scriptPubKey\n"
            "    \"amount\" : x.xxx,             (numeric) The total amount in " + CURRENCY_UNIT + " of the unspent output\n"
            "    \"height\" : n,                 (numeric) Height of the unspent transaction output\n"
            "   }\n"
            "   ,...], \n"
            " \"total_amount\" : x.xxx,          (numeric) The total amount of all found unspent outputs in " + CURRENCY_UNIT + "\n"
            "]\n"
        );
    RPCTypeCheck(request.params, {UniValue::VSTR, UniValue::VARR});
    UniValue result(UniValue::VOBJ);
    if (request.params[0].get_str() == "status") {
        CoinsViewScanReserver reserver;
        if (reserver.reserve()) {
            
            return NullUniValue;
        }
        result.pushKV("progress", g_scan_progress);
        return result;
    } else if (request.params[0].get_str() == "abort") {
        CoinsViewScanReserver reserver;
        if (reserver.reserve()) {
            
            return false;
        }
        
        g_should_abort_scan = true;
        return true;
    } else if (request.params[0].get_str() == "start") {
        CoinsViewScanReserver reserver;