mines ecu is just a remapped stocker, it will still do the same R+R when you get towards the end of the map, just not quiet as bad like you said.
buy a real ecu and get it tuned, my pick would be nistune with a z32 ecu.
and realistically, not many 25s make over 200rwkw with the standard turbo, usually around 180-200 depending on the dyno and other mods