The "Tough" Questions
The pink elephant in the room, to my mind, is the coupler chemistry used. So far there's been no mention of it by Stephen, though much more curiously, no one has asked.
Is this something you'd be willing to share?
I've noticed many times in the past that Mssr. Frizza will achieve things that just blow people away here, and he's always quick to point out that none of it's magic; it's a result of actual work, understanding the process and simply doing it. I greatly respect this, and it's model behavior in an internet community that's all too content with typing thoughts instead of doing actions. (*guilty as charged*) That's probably why we don't see him so often either.
With that in mind I wouldn't expect to have the whole process divulged just for asking, but I do think that if there is no incentive to keep it "proprietary" (and perhaps there is) then the details might be useful to someone who actually wishes to give this a go at some point.
On the other hand, I can understand how sharing it might cheapen your hard work. Hell, at least Daguerre got a life-time pension for giving away his process...
p.s. On "the Kodachrome thread", starting around post #3010 there is a discussion of color developers.