Backup & change EDID of Monitor

[ToastyX]

You should test it on a PC first. Changing the EDID won't change what the monitor will accept, and the EDID is likely write-protected anyway. The PS5 only supports 120 Hz with 1920x1080 and 3840x2160, so the monitor would have to support 120 Hz with one of those resolutions using the CTA-861 standard timing parameters ("Automatic (HDTV)" or "Native" with CRU).