So the succinct answer is no they don’t. Regardless this article contains a good bit of information on the differences between at true 10 bit panel, an 8 bit panel and 8bit with FRC.
PS: There is a good bit of anecdotal evidence that many who perceive/believe that PWM is the source of eyestrain may actually be more related to FRC.
In my own case, PWM doesn’t affect me, but I can notice/detect FRC (especially when it’s not well executed). More so with computer monitors where you are closer to the display. And for me, it manifests itself as a bit of fuzzy/un-sharpness to the image.
PPS: It is orders of magnitude more difficult and expensive to make a true 10 bit display versus an 8bit with FRC which is why they are more common.