May 2017 discussion in the main HDS thread, #19. Henry actually posted then.Got a link to those old posts? I'm happy to be educated, but I didn't find any posts on this topic with a couple searches and looking through about 20 pages of search results.
And it seems like you were being sarcastic, but it is possible to correlate measurements made with a light meter in an arbitrary reflective box back to measurements made using a spectrometer in an integrating sphere (and I know of at least one company doing exactly that for production measurements, for various reasons.) But it takes a bit of effort to get things to correlate well.