Generate Ember code coverage for a Selenium test run

Does anyone know how to generate Ember code coverage metrics off of Selenium tests? I've got several tests written in Groovy/Java.

I've found documentation of people doing this with Istanbul. One example is Front End Javascript Test Coverage with Istanbul Selenium.

There is also an Ember CLI Code Coverage tool that builds upon the instrumentation produced by Istanbul. However, from what I've gathered so far, this tool appears to completely wrap around the Istanbul instrumentation, thus only allowing code coverage statistics to be generated for ember unit and integration tests before build time. Where it stores its own mappings from the Istanbul results to Ember code is not readily apparent, at least not to a Java developer like me.

I'm looking for a way to generate a war file for internal use only that has both the Istanbul instrumentation and the mappings to the ember code, and that Selenium can trigger to generate the Ember Code Coverage report. Any insight on how to do this would be much appreciated.