You can implement a transformation on the /user object. Get /user is not a valid endpoint; so, Try it Out cannot be used in the API. After creating the API, use Get /{objectName}/{id} with your transformation name to test it out. For example, for an object called myUser, GET /myUser/me can be used to return the transformed data. To pull the status, use GET /user/{id}/status. If a transformation of the status object is needed, create a transformation object called myStatus and use GET myUser/{id}/myStatus. Again, the "try it out" functionality cannot be used and you will need to create the object in order to test it.
Also, the object discovery for these objects may not have all of the fields. In Cloud Elements 2.0 you can map in the UI to objects that do not show up in object discovery. In the meantime, you can map transformations with fields that are not showing up in the UI via the Platform APIs, (POST /instances/{id}/transformations/{objectName}).
