HU9 i assume if the older model was 0 pwm
No. Not sure for benq, but another brands can use few-three panels in one monitor.
But mostly monitors is flicker free. With my 2016y benq I dont have claims for PWM. But some models could have high-freq PWM which is not equal to flicker-free. I tryed lg replacement panel with 120khz PWM and return it. But it is my experince.
Also not sure it is no FRC. I mean, if all 8-bit are 6-bit+FRC, part of them are safty. For example, new models use A-FRC, which has similar to dithering effect (temporal blending)
Best way - to check monitor by yourself, keeping moneyback option. Unfortenantly. Or find sources with test for lights spectrums (better to have blue peak at 460nm than at 450, called low blue hardware solution), and proper PWM measurments (they can manipulate data using time window response, i.e. in 1sec measure you will see "flat line" but in 0.1sec you can see peak/dips typical for PWM)