I can only speak from my experience, but I purchased an Alienware 17 R3 a few years ago (2015 if memory serves), that had blacklight bleed on a UHD display. I was very concerned, because as you said these are expensive machines, and this seems to be a quality control issue. I hem-hawed over it for a few days (you can actually find the messages I posted here on it, if you search), and decided to do the RMA. The replacement system was a process to get, but when I finally got it, it too had the bleed. I decided that since I was under warranty I would wait it out, and do it later if necessary. However, over time the bleed did seem to subside. It never went away, but became much less noticeable. From what I understand, the plastic bezel around the screen does not have even pressure around the whole screen, which is what leads to the bleed. Over time, it stretches out, and seals better. Good luck!