I ran into a slight issue with retrieving the screen width using the credit card experiment.
There is a way to do this in my opinion, by recording two mouse positions and subtracting it to get the distance in pixels.
However, in this scaling experiment, because the units are “height”, the screen width is reported as 1/0.5 which turns out to 20 cm. (vsize=1)
I think the math is wrong unless we meant to say that it is 20% and not 20cm.
My screen in cm is much wider than 20cm.