Ha, yea these panels are really bright. They are outdoor panels so 5500 nits compared to the indoor panels which vary from 1000-1500 nits. I was just buying them for the added waterproof rating on the front of them... I doubt they would ever run anywhere close to full brightness, it's pretty blinding.
I'm definitely glad you were able to reproduce the issue and then figure out a solution, but I wish it was a little easier than having to rewrite other aspects of the software to compensate for other panels. I also wish I knew more about figuring this out, let me know if I can do anything to help!