NOTE: Since version 2.0, you need to provide a Youtube API key (https://developers.google.com/youtube/v3/getting-started) inside the userscript's source code.
Known issue: This currently breaks AJAX loading of video links (the website reloads entirely when you select a video).
This script adds
&user=channelID at the end of Youtube video URLs so that they can be used in uBlock whitelist pattern syntax.
It achieves the same thing as https://greasyfork.org/en/scripts/13226-youtube-whitelist-channels-in-ublock-origin but instead of reloading the video automatically with the new URL, which can get really annoying, this script changes the link when you click on them which means no need to reload.
Install the user script.
Create whitelist directives using the following format in uBlock Origin:
Note: This script will not work on embedded videos.