It’s definitely doable in one off quantities. And in fact people do it. Probably the most annoying thing would be dealing with length matching but honestly modern interfaces are much more tolerant than the specs imply. Power delivery could also be a sore point. So again, if you just looking to get a prototype working, it’s workable. But in volume. I wouldn’t go this route. This presentation lists some important things that are lacking in KiCAD when you really need to know the answer. https://archive.fosdem.org/2022/schedule/event/advanced_sim/...