I know nothing about chemistry and not going to challenge ADOX on their preference for 3-bath kits. But the obvious thing to ask is why didn't Fuji or Kodak, the two companies with the deepest R&D pockets, never launched blix-based chemicals for neither C41 or E6? According to old Photo Engineer posts the answer was that Kodak could not make blix to work with film. That's coming from the mid-00s era when they were at their peak. Coincidentally, 3-bath kits have only been available from small companies with no R&D departments, the same ones who suggest to soup up to 16 rolls in one liter contrary to Kodak and Fuji datasheets.
And of course, nothing comparable to Z-131 was ever produced for 3-bath products, with CMY density curves plotted for each round of chemistry reuse, etc. I suppose only the technical-minded users even care, while the market wants to pay for something that is good enough, cheap and easy to use. In that case I wish there was a datasheet covering what "good enough" means.
I am not trying to be a difficult customer. I simply see the difference in quality between C-41 products, for example the Bellini C-41 developer produced negatives that are notably easier to color-correct after scanning and show closer groupings of RGB readings on a densitometer than the last batches of Flexicolor chemistry. Another even earlier example was Cinestill C-41 kit. The first four rolls developed together in it were extremely hard to color balance. So much so that I had to re-validate my thermometer (it was fine). I know they're not all the same.
