I've made these parts to optimize the controller handling for especially games like Tetris or Doctor Mario. You can either print the whole 4-way button or use the shims to tune your controller as you like. Recommendation for the 4-qay button is to print it upside down, meaning the button side to the bottom and use soluble material as support. to get a smoother surface. Precision is key, the controller buttons are very sensitive and you may end up with a blocked controller. But nothing can be broken, it won't move a bit in worst case.
I've printed this with PETG as well as with PLA, isn't making a big difference.
Here I explain what's the main idea behind this modification:

Print instructions

Go for the finest quality possible. I've tested it with layer heigth 0.05 to 0.15 and it worked well.
PVA (soluble material) as support is recommended since precision is crucial and any remaining support material may render the part unuseable.