I had not seen that little note about complex profiles in building materials before, not sure how you get "from here to there".
[EDIT] Perhaps they just mean that the building material intersection priorities are active in CP's also, not that you can change them within the CP pnly... Unfortunatly whatever the case you can not use the fill orientation of "Fit to skin" which is exactly what you would normally use in this case.
However - I use the attribute manager to create copies of fills that I want to use in roofs (typically three, one for each orientation - soffit, barge board, and roof deck).
Then use the construction method and change to the icon with two fill handles.
By using this icon you can change not only the orientation of the fill, but its scale also.