I never liked 4F in the pan. As was said it sucks up moisture like a sponge and always find someplace to leak out when hunting.
I use Goex 3f for pan and main charge and get fast ignition. It also stays in the pan when hunting.
I buy from Graf's and Son. The more you buy the better the price, because it absorbs the HazMat fee.
I agree that T7 in the pan would be no ignition.