Well, we watched The Revenant yesterday and I noticed the top-middle faint yellowing without thinking about it. I only noticed it in some scenes, but it was there. My wife confirmed that my eyes weren't playing tricks on me. We didn't notice it in Deadpool or 10 Cloverfield Lane.
Hmm, what to do. I hate to be one to nitpick and complain about stuff like this, but that's a lot of money spent (to me) on the P75, to have to notice yellowing during normal viewing. I wish there was some easy way to correct it, like loosening a screw just a bit, or gently "massaging" the location on the screen. Although, I haven't tried either, so maybe I should.
What I'm worried about is sticking with my current display, and the possibility of the yellowing getting worse over time.