The same website makes metal buttons, resin buttons with real bugs inside, and more. Overall it’s not really anything I’m personally interested, but I love that the deck has enough support, and is tinker friendly enough, that stuff like this is even an option.
People on Etsy sell custom buttons, including Nintendo ones.
They’ve also recently added an option for layout-agnostic glyphs that show the position of the button (the four hollow circles with the button in question filled in) which I kind of prefer