Outside casing width limit in Wood Windows AC27 USA?

[Ignacio Azpiazu]

I am getting this 1 5/16" maximum width limit in the outside casing of Wood Windows AC 27 USA (I tried in Fixed and Casement). Doors don't have this problem. 

Is there something I am missing, some workaround, or no hope (and having to model some additional frame)?

casing width top limit in AC27 USA