The taillight mod is nothing special. The JDM spec STI’s (from what I’ve seen) use the circular lens for the parking light and the outermost part of the larger lens for brakes. Where the USDM spec STI’s use the larger lens for lights and the center lens for brakes.
So it is just switched from USDM to JDM. nothing special, but it something more to set it apart and make it “my own”