Okay, so I have seen Epic's paper that covers, among other things, how they did area lights in UE4 by the "representative point" method:
They specifically talk about how they needed to come up with a modification to the normalization factor for their BRDF to make the intensity looks close to correct. However, the one they list is for GGX, and I am using Normalized Blinn Phong. Sadly, I don't understand the math behind normalization.
Is there a nice simple way for me to find the normalization factor to use Normalized Blinn Phong with this area light trick?