Boomi NetSuite Upsert Response - Get External IDs of Upserted Records

Question

2020-07-09 EDIT: Apparently this is a defect. I finally got them to admit that, and they have filed a fix for it. I'll leave this open until the issue is completely resolved, though.

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I'm trying to clean up a Boomi integration that has three branches just to upsert records and then get the external ID from the NetSuite response. Every successful NetSuite upsert response has the external ID of the record that was sent, but Boomi does not have seem to be able to use the actual NetSuite response.

Example NetSuite response:

<soapenv:Envelope xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<soapenv:Header>
    <platformMsgs:documentInfo xmlns:platformMsgs="urn:messages_2019_1.platform.webservices.netsuite.com">
        <platformMsgs:nsId>##############################</platformMsgs:nsId>
    </platformMsgs:documentInfo>
</soapenv:Header>
<soapenv:Body>
    <upsertListResponse xmlns="urn:messages_2019_1.platform.webservices.netsuite.com">
        <writeResponseList>
            <platformCore:status isSuccess="true" xmlns:platformCore="urn:core_2019_1.platform.webservices.netsuite.com"/>
            <writeResponse>
                <platformCore:status isSuccess="true" xmlns:platformCore="urn:core_2019_1.platform.webservices.netsuite.com">
                    <platformCore:statusDetail>
                        <platformCore:afterSubmitFailed>false</platformCore:afterSubmitFailed>
                    </platformCore:statusDetail>
                </platformCore:status>
                <baseRef xsi:type="platformCore:CustomRecordRef" typeId="144" externalId="339487-2__RcvdType__38660884__6" internalId="4341574" xmlns:platformCore="urn:core_2019_1.platform.webservices.netsuite.com"/>
            </writeResponse>
            <writeResponse>
                <platformCore:status isSuccess="true" xmlns:platformCore="urn:core_2019_1.platform.webservices.netsuite.com">
                    <platformCore:statusDetail>
                        <platformCore:afterSubmitFailed>false</platformCore:afterSubmitFailed>
                    </platformCore:statusDetail>
                </platformCore:status>
                <baseRef xsi:type="platformCore:CustomRecordRef" typeId="144" externalId="314013-12__RcvdType__38661194__6" internalId="4339771" xmlns:platformCore="urn:core_2019_1.platform.webservices.netsuite.com"/>
            </writeResponse>

Boomi's NetSuite respone:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<Result>
  <id>#####</id>
  <success>true</success>
</Result>

Essentially, I just want to grab the external ID of the records from the actual NetSuite response. I've googled around, but I'm not finding anything that works... :/