Also (offering this completely non-confrontationally), what I've found that shows PWM implementation in the Note 8 is quite different from what Apple is doing with the X. I haven't looked for data on other Samsung OLED phones. Both the frequency and the amount (amplitude) of the pulse matter (or at least logically should matter; I'm not an eye or brain doc) to different users. TLDR; not all PWM is created equal.
PWM is never equal because no tech is always made equal. See: CPU binning lottery.