Bob, thanks for responding here, though just so you know my email was about a more straightforward screen-plate idea whereas this is kind of a theoretical proposal. Nevertheless, I think I see where you're going with this.
To me, I don't know the difference between an Imagesetter, a Lightjet, a Chromira, or a Lambda, but it certainly seems like they should be capable of doing the same kind of things, no? Or rather... if a Lambda can do continuous tone then it should be able to eat a hard-dot image for breakfast!
This seems like a brilliant idea that utilizes something you've already got in a fairly simple manner. I think it's brilliant, and awesome that you're thinking seriously about doing color carbon.
So in a sense I think you have answered the question in my email, but we can discuss it further when you get a chance.