https://hackaday.com/2017/09/12/hackaday-prize-entry-retrofit-a-nokia/ https://hackaday.io/project/21263-nokia-3210-retro-fit-board
Quote from the project log: "With the patched I submitted you can turn KiCad into a 'I know what I am doing' mode. Which meas you can place any type of via anywhere. You should not do it though. Vias are pretty well constraint by the manufacturer of the board. Since KiCad does not know of any layer thickness, production technologies and such it restricts to what is a sensible lowest common denominator."
Hmm so KiCad does not have a "PCB manufacturer constraints" input? How handy... NOT