Let's be specific so we don't get into unnecessary arguments.
Here an example of my typical multiple-exposure settings:
For the 1st exposure, I usually want the contrast, so I set my color head to
Magenta: 13 (my Fujimoto goes from 0 to 17) and Yellow: 0
Exposure: 14 seconds (due to high filter value obscuring more light)
For the 2nd exposure, I want to fill in the greys, so my setting is now:
Magenta: 0 and Yellow: 5
Exposure: 6 seconds
No dodging or burning is involved here. This gives me the right amount of contrast that I like on the print.
Can I achieve the same result using some combination of Magenta and Yellow with one single exposure? Maybe.
But the above method works for me, and it fits the way I think better, so I'm going to keep doing it.