MVCResourceCommand to send binary data inside native journal portlet - liferay

Question

I would like to send a binary file via an appended MVCResourceCommand I coded for the native journal portlet. But the program is unable to use the OutputStream provided by the resource request.
IOUtils.copy( input, response.getPortletOutputStream() );
Considering:
The code works perfectly on StrutsActions
In custom portlets, it also works
In StrutsActions:
IOUtils.copy( input, response.getOutputStream() );
However, the code throws an IllegalStateException, saying that the writer is being used when I call response.getOutputStream().
I know we can not mix these two
The code is not attempting to do so
I wonder if Liferay is doing something with that request before it reaches my extension of BaseMVCResourceCommand, this is specifically for that native portlet.
I checked the preview feature for a webcontect item, but its URL is for the view mode.
The URL is created from a portlet:resourceURL tag inserted through a JSP fragment and the command is in its own OSGi module.
For sure, the URL is correct and the command logs that it was hit, but the exception is thrown afterwards.
The portlet I am trying to change is the:
"com_liferay_journal_web_portlet_JournalPortlet"
Any thoughts?
PS: I know about the Servlet and Portlet ResponseUtils. but they also eventually try getting the stream, leadin to the same exception.
#Component( immediate = true,
property = {
"javax.portlet.name=" + JOURNAL, "mvc.command.name=/command"
},
service = MVCResourceCommand.class )
public class Resource extends BaseMVCResourceCommand {
#Override
public void doServeResource( ResourceRequest request, ResourceResponse response ) throws PortletException {
try {
response.getPortletOutputStream();
}
catch ( Exception e ) {
throw new PortletException( e );
}
}
}
Caused by: java.lang.IllegalStateException: Unable to obtain OutputStream because Writer is already in use
at com.liferay.portlet.MimeResponseImpl.getPortletOutputStream(MimeResponseImpl.java:75)
Update:
It seems this is the source of my issues (PortletURLImpl), still looking for a solution though:
if (lifecycle.equals(PortletRequest.RESOURCE_PHASE)) {
_copyCurrentRenderParameters = true;
}
When the URL is created it comes with all sources of garbage from the render phase. Including an MVCPath