Yes dealers can do it. I think a lot of people don’t seem to bother unless they get faults on the dash coming up. To be fair I would think there is probably only going to be issues if the adjustments to the alignment required were quite large. After I had my alignment done I checked the steering angle sensor and it still read zero in the straight ahead position, similarly the yaw sensor read zero too.
That said, I did carry out zero point calibration using techstream which is free to download if you’re reasonably tech savvy; you need a cable too to connect to OBD port to a laptop. If you get one make sure it’s firmware version 2.0.4, the lower firmware versions have limited functionality; most on eBay seem to be the lower firmware. You should be able to set yourself up with all you need for about £70 for dealer level diagnostics software which can read all ECUs on the car and perform error code reading/resets and configurations/calibrations. The process for zero point calibration is straight forward, the hardest thing was finding some level ground with less then 1 degree variation!