@DoctorG , no, it only adds a little error. The main problem is that image resolution is not taken into account by the browsers.
P.S. The EDID v1.4, which is communicated by my display, only allows 1 byte to set the screen size in centimeters (1 byte width + 1 byte height). So I cannot set it to my actual 59.6Γ34.1 cm. I'll see if I can do anything with that, like overriding the data with another EDID format and udev rules.