I finally tested the Xiaomi Redmi 3 for PWM and yes, it also has the infamous "mild flicker depth PWM at a 60~120hz-ish rate detected at all brightness levels" when filming at 240hz
surprisingly, despite this, this phone remains very very comfortable for me! in fact it is still one of the most consistently comfortable devices I own!
this is probably because because the PWM depth is too mild to affect me
the image on LineageOS 18.1 is extremely flat and most of the time everything looks rock solid. even watching YouTube videos feels amazing on this
but one thing's for sure, from all of the LCDs i've tested and have detected obvious PWM when filming anything other than white (and even in that case, it's actually still there if you lower the exposure, but cameras just do a bad job of making it visible on white in recordings)
the idea that """IPS LCDs don't use PWM""" is a MYTH and should not be trusted
same for "LCDs only use >10khz PWM rates that cameras cannot detect". this is also obviously not true as most LCDs I've tested that have "mild depth at all brightness levels" PWM appear to all use slow flicker rates
the only LCD I have not detected any PWM on at any brightness level so far is the 13-inch M2 MacBook Pro (the USB-C only Touch Bar version). although, of course, being a Mac it still has many color management, temporal dithering, and other pixel flicker issues
finally, "mild depth PWM" is not temporal dithering, because the M2 Touch Bar MBP is confirmed to use temporal dithering yet the backlight always appears stable on camera