I'll see "sparkles" or flashes of a solid color out of the corner of my eye, but never if I try to look directly at the screen to catch it. I chocked it up to some sort of PWM based lighting or something that's more detectable in my periphery because of how cones and rods work. Sounds like I might be close, but not quite?
I used to see a similar thing with a flatbed scanner that used RGB LEDs instead of a CFL tube. You could often see the flicker of the PWM signal they were likely using to control the brightness of the LEDs as solid flashes of red, blue, or green.
GP post said: "if you are sensitive for temporal hijinks" - I think I'm just really sensitive to temporal hijinks, especially in my periphery. I suspect most people are, as our eyes have higher concentration of rods to detect movement in our peripheral vision.
I've noticed that the quality of light I get out of a constant current light meant for videography is fantastic and has none of these "temporal hijinks", and I think it's because it simply doesn't flicker.
Still - none of this is said to undermine your good advice.