Keep that orange mask in mind when scanning with any unorthodox procedure. B&W Negative mode simply inverts the tones, black to white, white to black, a simple inversion the same as the Invert menu in photo editors. The new tone value is simply 255 minus the old tone. Color Negative mode does that inversion too, but Color Negative mode additionally filters out the orange color that is expected in color negatives, which has a very major effect to the resulting color tones.
So scanning anything other than Color Negatives in Color Negative mode is a serious no-no. It will heavily affect the tones of the original, removing expected orange that was not present (makes green and blue RGB values darker than red).
The purpose of the Film Type choice is to balance out a specific expected color shade of orange for that brand of negative film. Slide and B&W film does not need Film Type, any more than your slide projector needed to know film type. If one film type doesn't exactly do it, and no other choice is better, and if you still have a remaining color cast, you can use the color wheel (page 182) to tweak it more, typically moving the center closer or farther from "orange". We might assume that all frames on that roll of film will need a similar tweak, except that we know that images from different settings and lighting conditions vary substantially from frame to frame. There are no automatic answers in color.