Randy Mosher recommends Brown Malt for porters in mastering Homebrew. Yes, it isn't the same as the brown malt from a century or more ago, but IMHO it contributes a lot to a great porter. I use it at 10% of the grist and the members of my local homebrew club seem to like the results. One member asked for the recipe and then brewed it.
They talked about how it was done years ago which was basically guys with shovels would work frantically to keep turning the grain so it didn't catch on fire. Some of it would be burnt and other parts were completely unroasted. And that's what they called Brown malt. So if you extrapolate a little from that it just means we need today's brown malt in a small quantity and then add to that some very much lower roasted malt which still has diastatic power. So it goes without saying what you're talking about is spot on. I'm not sure we can ever replicate the Open Flame flavors and all that, without doing it manually I mean, but we can probably come pretty close to every beer with a little bit of effort.