[gpm]

For what it's worth I think of lot of guesstimates of PPD are likely a bit low. You can play games with lenses to increase it near the centre of the display where it actually matters (because your eyes don't travel that far away from straight forwards, so you can have much lower resolution in your peripheral FOV).

SimulaVR, a competitor with roughly half the number of pixels (2x2448x2448 = 11,985,408 vs 23 million), claims to go from 24.48 PPD naively calculated to 35.5 PPD near the centre of the display using this.

https://simulavr.com/blog/ppd-optics/