To me the real issue is size-up.
If the fire has not escaped the compartment(room) through the ceiling or the walls we still should fight it like any other room and contents fire. In other words, go in and get it before it does spread outside the compartment.
On the other had if we arrive and find fire or black smoke under pressure coming from the attic area the fire has left the compartment, or originated in that attic space, and we must knock down that fire before entry is even considered. The only exception to that may be to affect a rescue if possible in the living area. Fire in that attic space may rapidly lead to collapse or partial collapse of the roof from the trusses being attacked.
I guess my major point here is fire in a lightweight constructed building does NOT necessarily make that a surround and drown fire IF the fire is not attacking structural members.