Ok, I think to implement what you said, you will need to connect a switch to any of the spare GPIO pins (all spare pins are available in the pin out area at the top-left side of the circuit board). Then you need to modify the firmware code a little bit to define what should be triggered when the switch is clicked (there is already a manual_start_program function that you can call to trigger any existing program). The modifications probably won’t be more than 5 lines of code, but it does require a little bit of programming background to implement.