This design is actually extendable, you just have to increase the sensor detection length and add another bearing with a controller in the same orientation as the other ones before it. Customize the angles just like the second controller. And hook up another button. :P
Note: Multiple buttons activated at the same time might cause some problems. Set the controllers to turn 15 degrees for best performance.
The design isn't mine, although I did make it more compact, using the controller for the door in the support structure for the mechanism. The original design was by noKacper24, and you can watch his video here. • Video