I needed to sand the layers of plastic to add diffusion.
Then, I reattached the rear PSI and gave it a test.
Photos always show hot spots more than they show to the eye, but I did do some minor adjustments after this picture was taken to the diffusion and PSI alignment with the hole in the dome, and I was satisfied with the results. For now.
I also added foil tape to the inside of the PSI holder. It's just for diffusion, so it doesn't have to be perfectly smooth. (I could claim that I made it messy to help with the difussion, but I can't/won't.)