If your roof drains to center drains.....No ....Never !!
If your roof drains to the edges....Yes....from a 2 to 4 slope, I would reccomend that over anything else. You may need to install ice railings if your edges are over walkways or bump-outs to prevent slab damage from heavy ice falling. From 2 down to the apex or high point,...this flatter slope would require soldering the seams.