If we can get the Files App to open as a regular webpage, we can run and debug UI tests in real time and see the results.

This would involve getting the main app page to open, the Javascript to run correctly, as well as mocking out the various API calls that are (conveniently) inaccessible outside of packaged apps (i.e. FileSystemPrivate).

This may be an impossible task, or it may be fairly simple. Only one way to find out :^)