Why doesn't the list of included fonts change when changing the subset in Google Fonts?

Question

css

I connect the Roboto font for the site.
Google Fonts provides an interface for setting up the included font, where you can choose the thickness, subset. Then it gives a link:
https://fonts.googleapis.c...subset=latin,cyrillic
https:
//fonts.googleapis.c...subset=cyrillic and the fonts in the given css does not change. At the same time, both greek and vietnamese are loaded - extra kilobytes and seconds of download for clients.
How to cut off unnecessary subsets of fonts and include only Cyrillic and Latin? Or is it a feature of the font?

Answer 1

This is a feature of the font - Roboto's plug-in set includes all encodings.