Prius 3, reset steering angle sensor

Hello,
Few weeks ago I wrote about slight pulling to the right here. Today I talked to a guy at a local service shop and he told me that he had the same problem with a Subaru with electric steering after alignment. He said to check the angle sensor with the diagnostic tool and if it's not at 0 degrees when the steering is right, it must be reset/re-initialized.
So, I hook up the Techstream and the "Steering angle sensor" showed 4.5 to 6 degrees when the steering is in straight position (according to my view).
I looked for the option to reset it, but found only "Torque sensor zero point adjustment" and "Rotation Angle Sensor Initialization". I successfully completed the learning, but nothing is changed, still the "Steering angle sensor" shows 4.5 - 6 degrees deviation.

According to the documents, to do the "Torque sensor zero point adjustment" and "Rotation Angle Sensor Initialization" correctly, there must be two DTC logged - C1515 and C1525, so the Techstream cleared the calibrations and the errors popped up. After the procedure, they disappeared.

So, how can the "Steering angle sensor" can be reset? I was looking in the ABS/VSC/TRC - > Utility and EMPS -> Utility sections, but found nothing... Any help how to do it?

 

Found 2 manuals about the procedure after wheel alignment. One is for Tundra, and the other is for Prius 3. Both don't change the "steering angle sensor". Today had the negative terminal disconnected for a minute and after that, the "steering angle sensor" readings didn't change at all.
It's a mystery for me, on other cars there is an option and everything goes to 0.0, but here this does not happen.

Is it possible that this "steering angle sensor" be the real angle between the sensor and steering column and it doesn't have to be exactly 0 degrees when straight and every calibration/learning/reset be the adaptation to this value instead actual resetting the sensor... I can't find any other logic behind this

 

Little bump
Today I did everything again step by step as it is in the manual. Of course, nothing changed. The car still pulls slightly right on the MOST of the roads. There are some that it goes straight and I think I'm going crazy

While looking at the live data, I saw interesting parameter - "zero point of steering angle". It stays at 0.0 degrees after the procedure even if I turn the wheel in 45 degrees angle, for example. After the "wrong" 45-degrees learning, I did a test drive and strangely, there was nothing unusual - no error lights, nothing. Just before turning off the car, I saw that "zero point of steering angle showed something different than 0.0, but after turning it on again it was 0.0 again. I searched a lot, but I can't find anything specific about that parameter. Can it be set/learned manually?