As a possible workaround, maybe you can create an interceptor which used get the header element and put it to the Message, then,  sam-agent will get it and store into DB.

import org.talend.esb.sam.agent.message.CustomInfo;

public void handleMessage(Message message) throws Fault {
   ......
   Header header = ((SoapMessage)message).getHeader(...);

   Node key = (Node)header.getObject();
   String value = headerNode.getTextContent();
   
   CustomInfo customInfo = CustomInfo.getOrCreateCustomInfo(message);
   customInfo.put(key, value);
   message.put(CustomInfo.class, customInfo);
   ......
}


and add both your interceptor and sam-agent feature into jaxws:endpoint or jaxws:client like this:
        <jaxws:interceptors>
            your interceptor
        <jaxws:interceptors>
        <jaxws:features>
            <ref bean="eventFeature"/>
        </jaxws:features>

Didn't test hopefully this workaround will work ~