Is it acceptable based on ACI 318 18.1.3 to assign the column strip width of a beam in the banded direction of a two-way slab as "full width"? I've seen several recommendations that you should only consider the full flange width for the axial compression calculation only, but that for flexural design one should really be using the effective flange limitations of 8.12.
If your goal is to have the entire demand on the full tributary width considered, but to have the capacity based on a narrower effective flange width, that's when we advise people to use the design strip option, "Design Column Strip for Column + Middle Strip Resultants" along with a code T-beam or manually set column strip width.
If you are trying to get the program to use one width for axial calculations and another width for flexural calculations, we can't do that since the two forces/stresses/strains are inextricably linked.