There is nothing wrong with UV map layout. It looks good to me. Plus Epic’s subsidiary did the art (Infinity Blade guys), so it’s safe to say they know what they are doing with art for UE4 engine.
By “production building” do you mean Production quality for lighting or did you actually deployed production build for a platform ?
If all you did was to build with Production quality, then for whatever reason that doesn’t work for me in my other project (I haven’t tried building this test case with Production quality). Lightmass settings are identical with FPS template, lighting setup is identical too (same lights, same settings).