Anderson phone support was a joke. I won't go into it.
Here's the jamb extensions:
If facing the RO, what purpose does it have other than to weaken and promote splitting when nailed?
If facing the visible side all I can figure is to aid in nailing at an angle...as well as to weaken and promote splitting when nailed?
If you ask me it will look like crap if it's visable. The channel at the sill will end up being a collection place for any moisture/condensation. Window going in bathroom. Inside/outside temp difference can be 90-100 degrees mid-winter. Let's not go off on a tangent about ventalation fans, opening doors and all that.
Thanks, Al...