I'm glad you enjoy the extension!

I apologize for reading your comment 3 months after you posted it.
I pushed an update that adds this capability (version 1.1.19).

I translated your message to English to understand it.
If the translation is correct, you're having an issue in which the extension doesn't actually influence the video size.
If you resize the video yourself, is your preference being kept?

Edit: Recently I pushed an update that fixes this problem.