[Scribus] argh! no true duotone ink support in scribus for photos

[linuxlingam]

dear all,

i have a new design project which i am attempting to do in two-inks: one
black, one a pantone ink.

i understand how to mark an ink as pantone in scribus,

BUT,

i wish to create the photographs as duotone imagery. i launched
cinepaint as well as gimp2 but they only handle rgb or grayscale. i can
'simulate' duotone by converting rgb>grayscale>rgb and applying a hue or
colorizing the photo.

however, how do i handle two-ink photographs in scribus? assuming i can
only input a grayscale in scribus, would be wonderful if scribus allowd
me to covert a grayscale to duotone or tritone INTERNALLY.

any suggestions?

:-)
LL