There was a time when blurred fonts were some of a (small) hype. The tricky part is that phosphor response isn't linear, but sinusoidal, and that you had to scale this with font size… (You could make this an axis with variable fonts, though.)
Since the VF extension requires a state machine that can modify the font, it might be able to accomplish that, but my very quick read of the spec didn't let me grasp whether the SM executes once, or whether you can run it repeatedly.
(I am not a sufficiently clever person, obviously, and you probably wouldn't want to burn cycles on simulating that anyway. Nevertheless.)
