Greasy Fork is available in English.
Tries to turn embedded Youtube videos into thumbnails - this is based on "Stop Overzealous Embedding" https://openuserjs.org/users/ConnorBehan
< Convert Youtube Embeds to Image Linksについてのフィードバック
Thanks, haven't used Greasy Fork in 7 years and had forgotten all about this. Glad to hear I did something right once :-)
Still working in 2023.
Embedded videos load for just a second but script cuts them out of the page code (and out of browser memory, to speed up the page) and replaces them with the thumbnail image linked to the actual YouTube page. Nice. I will definitely be using this.