Actually, you already have support, you just need your ECU rom defined. This can be done by downloading your rom, joining Romraider, and uploading your rom while being a bit patient. Edward uses Romraider to assist in some rom definitions.
Not to be too much a shill for Edward, I only mentioned him because he can guide you through tuning remotely. I'm in Pennsylvania USA and Edward is in Barbados. I'm over 300 miles from the nearest Subaru tuner so its not exactly doable with a family which made him ideal. The fact that he can do the job made it worth it.