Did you read Dan Margulis books on color correction and photo editing? Some of his tricks needs forks in processing graph for sure, and is not expressible in P

Did you read Dan Margulis books on color correction and photo editing? Some of his tricks needs forks in processing graph for sure, and is not expressible in Photoshop Layers in non-destructive, configurable way. Channel extraction and replacement after some processing like blurring and masking, for example. Sometimes in different color models, like replace RGB Red channel with CMYK Magenta one, blurred and masked with Black.