What we need to do is one of the following:

• modify the InjectTemplateListener to not inject a template if a 404 is detected
• modify ActionController::notFoundAction() to set an explicit template on the returned view model

The former is the easiest route, and allows you to use the site-wide 404 template easily. The second allows for per-controller 404 templates, but would require code for inflecting the module namespace and controller name -- which is currently encapsulated already in the InjectTemplateListener.