KM yes I did it, when I set it to 68 or 70 without any filter it's way to bright for me and after one minute - pain, even on next day I've tried and max brightness for me was around 5. I know when I feel direct strain then it's almost impossible that it will better.
Filter I use with LG as I wrote and there works fine, but on 3T it's better then without but not the same as with LG. It's surly connected with color tint, but can't find this the best one even when I compere to LG, maybe some one will create this the best one and I don't think PWM is making my strain. When I saw video on youtube most of them show that OP3 or 3T have PWM but screen is way better then my iPhone 6 which have 0 PWM. When I mess in settings in iP 6 where you can change colour tint it's getting better to use but not as LG.
I had a lot of hope with this 3T, I've tried many phones and surly it is one of the best ones but not the same as my old G2. Now G2 is getting slow so when I have to I will try once again one plus maybe 4 or 5 we will se what will be next or I will try to stay once again with 3T on min brightness.