I had eye strain due to PWM on the iPhone 11 Pro Max, had to sell it due to how bad the eye pain was. Even after weeks, couldn't get my eyes used to it.
Bought a Samsung Galaxy Note 10 plus which still had PWM but unlike the iPhone, my eyes stopped having symptoms after 4 days of using it. And when it hurt my eyes during those days it was much less terrible.
I haven't tried the OnePlus with DC dimming, sounds like the best option and I was going to buy it too if the Samsung Galaxy Note 10 plus didn't work.
I'm glad it worked with Samsung though since it's the phone with the most features and a much more trusted brand. Other android brands just don't compare in my opinion.