"Now you can have infinite variations of a font, all worse than the first"
It looks cool. But what's the use of it? The only benefit/usage I can think of is to adjust the font weight because now you can generate more weight variations besides the existing "light, regular, bold" option.
I don't think people should (or need) change other parameters (e.g. cap height, x-height). Otherwise it will become a completed different font.
This is a super fun way of exploring type - giving the cursor the control without explicitly saying so is neat.