Can't see why not. Almost the same ecu, basically the same engine, just detuned, so the same style ecu is needed at the very least, hence tunable. A guy called Raijin does them but he's on a bit of a hiatus as of about a month ago to spend more time with family. There are others out there willing to do it too, just got to ring around. What part of nz are you in?
I would have thought the zerosports would be perfect since it controls when the switchover occurs so you could alter it to change according to how your wife likes to drive, but still just putting a plaster over the real problem, tuning will solve that and more.
Chuck a can of subaru upper engine cleaner through aswell, cleans all the crap off valves and the rest, costs around $20, so you're not really losing anything if it doesn't help much