But C1 V6 is the FIRST version where you can actually make your own Color>B&W conversions that are not based on some sort of profile.
not quite correct. The "B&W" (neutral) profile has always provided a "uncorrected" B&W conversion (if you want so: a desaturated "no colour correction" profile). Starting from here you could use the Color Editor to adjust the B&W files. It was not very intuitive to use when you are used to a chanel mixer workflow. But basically the tools have always been there.