Sending back proxy inbound validation

Hi experts,

We have with one requirement here which I'm not sure if this is possible to attend. We have a SOAP x Proxy scenario, and when we sent a message with some invalid information (like one field which should have 3 characters, but are being sent with 5) and Proxy infrastructure are rejecting the message with the below error:

<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>

- <!--  Inbound Message

  -->

- <SAP:Error xmlns:SAP="http://sap.com/xi/XI/Message/30" xmlns:SOAP="http://schemas.xmlsoap.org/soap/envelope/" SOAP:mustUnderstand="1">

  <SAP:Category>XIServer</SAP:Category>

  <SAP:Code area="INTERNAL">INCORRECT_PAYLOAD_DATA</SAP:Code>

  <SAP:P1 />

  <SAP:P2 />

  <SAP:P3 />

  <SAP:P4 />

  <SAP:AdditionalText />

  <SAP:Stack>Erro no processamento do payload de mensagem. Ocorreu um erro na deserialização em o programa ST /1SAI/SAS576C0498218C0ACE08E3. O comprimento de &quot;IP210000000000&quot; excede o comprimento máximo &quot;12&quot; permitido com tt:maxLength.</SAP:Stack>

  <SAP:Retry>M</SAP:Retry>

  </SAP:Error>

What we want to do is to catch the SAP:Stack message and return back to the client system. Is that possible?

I know that the best way to do that is using the message validation of SAP PI, but as its very difficult to maintain (xsd needs to be copied to file system), we're thinking here if we can propagate this SAP:Stack message to the client.

I really appreciate any help. Thanks.