The Waveshare Game Hat has one more button that most people have never used. In fact it is just under the joystick
if you push on it, but it is not connected to the Gpio's.
This button is connected on one side already to the ground. So a simple wire is enough to connect it to
the wanted Gpio pin to activate it as hotkey button, missing for the moment in the layout.
I used Gpio 17 on pin 11, free in most similar board layouts.
Apart from the added wire you need also to change the parameter line in the gpio controller,
that's all 🙂