Also, is the Aveo auto a three speed with a lockup torque convertor? If so, they are programmed to go into torque convertor lockup at a certain speed and not before seeing in most cases the manufacturer thinks the engine doesn't have enough horsepower and/or torque to hold the lockup at a lower speed without lugging the engine.

I have a feeling that the 4th gear is the torque convertor lockup and not an actual gear.
I suggest you re-read my original post and try to comprehend it before responding.

The transaxle is the Aisin 81-40LE. It is the only automatic transmission ever used in all Aveos made since 2004. It IS a four speed transmission. Everything about that specific transaxle is documented, including the specifications for shift points in the Aisin service manual, which is available on-line.

Your conjecture has no basis in fact; as such it amounts to misinformation.