Writing new code could considerably reduce its complexity and make things much easier. After a few years with FSP, I'm convinced that writing clean code would be cheaper than the FSP integration with all its avoidable complexity. Intel might not like it, but you could reach proper coreboot support much faster without FSP.
Assuming that's true from an engineering perspective and we're clear to publish all code/info needed, we'd first need to invent a way to send an electric shock thru the keyboard to users who complain to (or about) Intel when something goes wrong with the code.