We have a Arkay print dryer at the darkroom. I always stick my MGIV facedown with low speed high heat. When it pops out it's tacky. Then, I stick it back in face up, and it will come out pretty flat. I'll usually run it through a 3rd time with lower heat and a faster speed just before filing it in my art binder.

Once in the binder for a day, it will remain pretty flat for fiber.