Because a steel frame conducts the outside temperature so much easier than wood, it's necessary to provide some resistance to that thermal flow.
So we're now sheathing the exterior with a foam board to insulate the steel studs.
A helpful side effect is that the interior & exterior spaces now have definition, & you can get a better feel for the eventual size & volume of those spaces.
Eventually, a second, more sturdy sheathing will cover the blue board. And the walls and roof rafters will be sprayed with foam insulation, all the way to the roof decking.
In effect we'll be creating a "thermos bottle" effect to keep our energy bills low.
It costs a bit more to build this way, but I always tell clients that " You can pay now, or pay later, when the power bill arrives."