This script will help you build temporary playlists from your subscriptions. A button "Add to new playlist" will be added to each video that is listed on your "Subscriptions" page, this will create a playlist link with those videos you added there.
Useful when skimming your large subscriptions list for music or interesting videos that you want to watch in one go.
The script makes use of Youtube's
watch_videos feature. It is unfortunately limited to 20 videos.
You can also just copy the video ID list and add it to Synctube/Cytube or similar sites.
A playlist URL might look like this: