This is something really simple but very helpful. If you want to make the tediously repetitive testing of your game go faster, you can speed up the entire game with the script call:
Graphics.frame_update=160
Frame rate at normal speed should be 40, so that's supposed to be 4 times faster (it likely won't achieve that exactly due to pc constraints, but will still make things quite a lot faster).
So to make it even more convenient, you could make a common event like this:
This will make it so that when Switch 1 is on, you can turn on the speedy mode by pressing 'W', and switch it off by pressing 'Q' for the parts that you need to tread carefully. Or you can use whichever other input keys you prefer, of course.
Hope that helps!