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.
{
    std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
    CWallet* const pwallet = wallet.get();
    if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
        return NullUniValue;
    }
    if (request.fHelp || request.params.size() > 4)
        throw std::runtime_error(
            "listsinceblock ( \"blockhash\" target_confirmations include_watchonly include_removed )\n"
            "\nGet all transactions in blocks since block [blockhash], or all transactions if omitted.\n"
            "If \"blockhash\" is no longer a part of the main chain, transactions from the fork point onward are included.\n"
            "Additionally, if include_removed is set, transactions affecting the wallet which were removed are returned in the \"removed\" array.\n"
            "\nArguments:\n"
            "1. \"blockhash\"            (string, optional) The block hash to list transactions since\n"
            "2. target_confirmations:    (numeric, optional, default=1) Return the nth block hash from the main chain. e.g. 1 would mean the best block hash. Note: this is not used as a filter, but only affects [lastblock] in the return value\n"
            "3. include_watchonly:       (bool, optional, default=false) Include transactions to watch-only addresses (see 'importaddress')\n"
            "4. include_removed:         (bool, optional, default=true) Show transactions that were removed due to a reorg in the \"removed\" array\n"
            "                                                           (not guaranteed to work on pruned nodes)\n"
            "\nResult:\n"
            "{\n"
            "  \"transactions\": [\n"
            "    \"address\":\"address\",    (string) The bitcoin address of the transaction. Not present for move transactions (category = move).\n"
            "    \"category\":\"send|receive\",     (string) The transaction category. 'send' has negative amounts, 'receive' has positive amounts.\n"
            "    \"amount\": x.xxx,          (numeric) The amount in " + CURRENCY_UNIT + ". This is negative for the 'send' category, and for the 'move' category for moves \n"
            "                                          outbound. It is positive for the 'receive' category, and for the 'move' category for inbound funds.\n"
            "    \"vout\" : n,               (numeric) the vout value\n"
            "    \"fee\": x.xxx,             (numeric) The amount of the fee in " + CURRENCY_UNIT + ". This is negative and only available for the 'send' category of transactions.\n"
            "    \"confirmations\": n,       (numeric) The number of confirmations for the transaction. Available for 'send' and 'receive' category of transactions.\n"
            "                                          When it's < 0, it means the transaction conflicted that many blocks ago.\n"