Am I stupid?

The difference in laptop and desktop is the ease with which you can use it to work on your car. If you take your desktop and set it up near to the car (where this is determined by the length of the cable that goes to the diagnostic data port on the car) then you could save lots of money on the software needed to figure this out.

The Steering Angle Sensor can be cleared by turning the steering from stop to stop in a continuous motion. You can Google it for precise directions, but I started the car and turned the wheel to the left to the stop, then turned to the right to the stop in a continuous turning motion, then turned back to the center. The steering angle error cleared and the trifecta went out. If you disconnected the battery, then you would need to reset the steering angle sensor (SAS).

Yeah good point!

Nope. If just clearing that light after battery disconnect... lock to lock is the way to go.