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.
"    \"blockhash\": \"hashvalue\",     (string) The block hash containing the transaction. Available for 'send' and 'receive' category of transactions.\n"
            "    \"blockindex\": n,          (numeric) The index of the transaction in the block that includes it. Available for 'send' and 'receive' category of transactions.\n"
            "    \"blocktime\": xxx,         (numeric) The block time in seconds since epoch (1 Jan 1970 GMT).\n"
            "    \"txid\": \"transactionid\",  (string) The transaction id. Available for 'send' and 'receive' category of transactions.\n"
            "    \"time\": xxx,              (numeric) The transaction time in seconds since epoch (Jan 1 1970 GMT).\n"
            "    \"timereceived\": xxx,      (numeric) The time received in seconds since epoch (Jan 1 1970 GMT). Available for 'send' and 'receive' category of transactions.\n"
            "    \"bip125-replaceable\": \"yes|no|unknown\",  (string) Whether this transaction could be replaced due to BIP125 (replace-by-fee);\n"
            "                                                   may be unknown for unconfirmed transactions not in the mempool\n"
            "    \"abandoned\": xxx,         (bool) 'true' if the transaction has been abandoned (inputs are respendable). Only available for the 'send' category of transactions.\n"
            "    \"comment\": \"...\",       (string) If a comment is associated with the transaction.\n"
            "    \"label\" : \"label\"       (string) A comment for the address/transaction, if any\n"
            "    \"to\": \"...\",            (string) If a comment to is associated with the transaction.\n"
            "  ],\n"
            "  \"removed\": [\n"
            "    <structure is the same as \"transactions\" above, only present if include_removed=true>\n"
            "    Note: transactions that were re-added in the active chain will appear as-is in this array, and may thus have a positive confirmation count.\n"
            "  ],\n"
            "  \"lastblock\": \"lastblockhash\"     (string) The hash of the block (target_confirmations-1) from the best block on the main chain. This is typically used to feed back into listsinceblock the next time you call it. So you would generally use a target_confirmations of say 6, so you will be continually re-notified of transactions until they've reached 6 confirmations plus any new ones\n"
            "}\n"
            "\nExamples:\n"
            + HelpExampleCli("listsinceblock", "")
            + HelpExampleCli("listsinceblock", "\"000000000000000bacf66f7497b7dc45ef753ee9a7d38571037cdb1a57f663ad\" 6")
            + HelpExampleRpc("listsinceblock", "\"000000000000000bacf66f7497b7dc45ef753ee9a7d38571037cdb1a57f663ad\", 6")
        );
    
    
    pwallet->BlockUntilSyncedToCurrentChain();
    LOCK2(cs_main, pwallet->cs_wallet);
    const CBlockIndex* pindex = nullptr;    
    const CBlockIndex* paltindex = nullptr;