There really is no difference in the procedure.
Line art is of course different.
This keeps the colored stain separate. It is easier to touch up to remove a blue stain when nothing else is blue, than if you let it go to gray and blend in with the photo objects. Then convert back to Gray when touchup is complete. Conversely, color prints to be converted to a Gray Scale image are desirably scanned first in color mode. The Green cell alone is perhaps best for Line art, but it may not scan a color photo perfectly.