I use the Saunders 670MXL dichroic enlarger and numerous times a suboptimal negative has been easier to print by using the split-grade technique, despite what the aforementioned article says.
Are you talking about getting in between grades which you can do anyhow with your colour head or do you mean that you give some exposure with a high contrast setting and some with a low contrast setting? The article says that the resulting curve shapes are identical, I'm just confused as to why there is such divergence of opinion over this subject.
It is said that we remember the important things, if true, why photograph? I forget, so I photograph.