@DevinNj @Tsepz @Hulldown @upandown @chabig @mac4good84 Thought I'd update you all. I managed to book a Genius appointment, attended today. I printed off photos as well as saved them to a folder on the photos app. Showed them to to the guy who saw me, he tried replicating it but couldn't seem to. Asked for a second opinion with a colleague, and after filling out their documentation, arranged to have the screen replaced. 1 hour later, I picked it up. Uniformity appears to be perfect now. Thanks for your help!
TLDR; they replaced the screen on my phone, and now the display is even and better than ever.
EDIT: I believe he looked at the live photos of the problem that I took and gave me the benefit of the doubt, as well as the knowledge of his colleagues into the uniformity (seemed to have heard of the issue).