Mine straight as can be. It’s not the Spigen one. There’s an approx 1-1.5mm gap all the way around. I completely understand your stress point of view. That’s me also.The black border should stop at the screen, the rest overlapping the bezel. Needs to be fitted 100% straight though.
I know I've not lost pixels as when I invoke the app switch/shut down thumb swipe the shrinking image is exactly what I see full screen.
Had to remove and reapply my Spigen Alignmaster about 5-10 times before getting it perfect. The template had too much leeway to rely on. Then after getting it perfect I had to carefully lift corners to use the dust removal stickers for the odd piece of dust/lint that would get in on each attempt. Stressful, lol.