The TDML Runner only uses the ScalaXMLInfosetInputter/Outputter when running tests. This means that other Infoset inputters/outputters (JDOM, w3c DOM, json, XML Text) are essentially never tested as part of our full test suite. We need a way to run all of our tests with the different infoset representations so that they get adequate test coverage. We probably don't need to do this for every build, so it's probably okay if it's a somewhat manual process (e.g. setting an environment variable or config option in the TDML Runner), but it needs to be mostly automated.