Quoted from aKa:
I guess they are not essential for now, but I'll keep that in mind. Funny that they were deliberately cut ...
They were cut for an "instant fix", but should have been replaced as soon as possible.
Just like if your car is low on radiator coolant, you will put in water to get the car back on the road; but as soon as possible, you replace the water with proper fluid.
Without the caps properly installed, your switch will not register every time the ball hits it.