Sounds like my experience in making seps from color negs wasn't as good as yours.
The "one shot" camera was certainly easier than making seps from a chrome or neg, but the image size was rarely consistent, so you had to fiddle with enlargement size to keep the matrix films in register. You also (ideally) had to do substantial postmasking to address color and contrast issues.
Holmburgers, those digital sep. negs are looking a lot better. In fact, Tartaro was experimenting with a hybrid digital neg dye transfer at the end of his career. Digital meant (even then) a lot of color and curve control + no flare.