Well, keycaps potentially got added to the list of things to design, but otherwise the basics are the same. There would just be an adjustment to the 2-D “plate” files you’d need to use, and you’d run into the complications from a printer build plate sooner (depending on printer and keyboard size). You might not need to go a full 20-25% though. Just 5 or 10 might be enough and then you could maybe still get away with “normal” keycaps. Different shape families of keycaps have different names, and the XDA (sold by every random reseller on Amazon) or ISA (made for one specifix brand, XVX) both have pretty large top surfaces that would help with making your fingertips comfortable and blunting the aesthetic hit of altering a dimension we’re subtly used to.