Our flicker fusion rate is different for the fovea and nearby central vision vs the peripheral vision.
The central vision is slower-response, higher-resolution, and of course color vision.
The peripheral vision is monochrome and has a much faster flicker-fusion, tuned to picking up motion in the periphery.
So, the same flicker rate that you never notice on a small monitor may flicker annoyingly on a large monitor. To check that a setup will not flicker for you, set it up in a darkish room, focus around 70°-100° to one side of the monitor so it is in your peripheral vision, and both look at one place and notice your periphery, and also move your focus quickly from one place to another and notice if the screen blurs like bright stationary objects or looks like a discontinuous blur (really easy to get that effect with fluorescent lights). Do it both left & right and towards the ceiling. If flicker shows up in these tests, it will still eventually bug you when looking directly at the screen, even if it isn't as noticeable because your focus is in the center of your vision.