I am not familiar with that brand but it sounds a lot like THERMORE...it is probably the insulation pores that are constricting not the pores of the breathable membrane. It is critical to have breathability even in the cold for moisture transfer. If it is like THERMORE, however, then it is considered a 'smart' insulation that reacts to the body heat you are putting off and as it warms up there is a structural change in the insulating fibers that allows for more heat to escape. Conversely, when the temperature drops the fibers constrict to restrict the release of body heat.
The reason these fibers are rated so highly is because the challenge in active, outdoor sports is to remain at a constant temperature - balance is more important because it allows the body to adapt instead of sea-sawing from hot to cold.
Hope this helps!
See ya on the slopes!