Ride heights on the Impreza chassis are largely determined due to suspension geometry. Once the front control arms go past level, the front suspension design causes camber to go positive very quickly which is very bad for handling.
It is so bad that in stock Autocross class where you can only change the front sway bar, not rear, they put massive
32mm bars on and have had great results.
The improvement in contact patch and enhanced turn in far outweighs the reduced suspension complieance and does not induce additional understeer as you would normally expect.