Divided Development, B&W or color
I have spent years experimenting with various B&W formulas, published and my own creations. My gosh, who wouldn't want a developer that was film, time, or otherwise so compensating for every situation? But truth be told, I NEVER got one that worked well. Either thin negatives or large grain. Many say that is because modern films aren't like those of 80 years ago. Whatever the reason, forget it.
Thats B&W! Imagine the complexity times ten or twenty for color. Patrick Dignan published a formula for divided development way back when. I've never tried it, but I've never seen anyone on this or other forums claiming "Eureka!" I do not recall one instance of his formula working.