You are right Mustang! :) Thanks for the screenies.
Although I added just a little bit, step by step. It's now at 0.05 ;) , but I also changed the hdr level/brightness in hdr.lua as well, to overcome what you have highlighted. With adjusted sweetfx settings, it's very pretty now.
I will need a bit more time to figure out myself what is possible.
It's a little search here to not have blur in the cold hdr setting, but to keep it as beautiful as possible from your mod.