Greasy Fork is available in English.
A lightweight and non-intrusive userscript that control video playback and set the preferred player size and playback quality on YouTube.
< Yays! (Yet Another Youtube Script)についてのフィードバック
This can be disabled by clicking on the blue slide toggle above the related videos, or find the option in the settings menu.
Could we get a feature to disable YT new Autoplay?
What we can see at the top right: "When autoplay is enabled, a suggested video will automatically play next."