2021-01-06, 02:42
You can also get your personal Watch Later Playlist ID by the way of Google Takeout, just export your YT Playlists and look in the archived .csv files.
Didn't test if the plugin will take the custom IDs directly, but I simply made custom lists for Watch Later (also for History, but sadly that ID is noted in the Takeout) to be on the safe side.
You just have to enter the Playlist ID directly in your Browser, followed by &disable_polymer=true (for example https://www.youtube.com/playlist?list=YOURPLAYLISTIDHERE&disable_polymer=true),
and even the available special lists behave like a standard playlist and let you add all videos to another list per the ... menu, etc.
Didn't test if the plugin will take the custom IDs directly, but I simply made custom lists for Watch Later (also for History, but sadly that ID is noted in the Takeout) to be on the safe side.
You just have to enter the Playlist ID directly in your Browser, followed by &disable_polymer=true (for example https://www.youtube.com/playlist?list=YOURPLAYLISTIDHERE&disable_polymer=true),
and even the available special lists behave like a standard playlist and let you add all videos to another list per the ... menu, etc.