Wait... so operating at 100% brightness mitigates this? I bought this mac and have been reading about this. Stare at computer 15+ hours a day coding, but I also never use anything less than 100% brightness.

If you have a modern-ish phone to go with that Mac, try taking a slo-mo video of your screen (preferably with content with decent sized patches of something other than black or dark gray) at different brightness settings. Maybe even make a big gradient and display that at various brightness settings.

PWM is usually only used for dimming. So at 100% brightness there is no PWM being used. I'm not sure how this apple monitor works, but that's the basic gist for most screens that use PWM for dimming.