Let playback run on its own with Automation
Automation blocks autoplay, keeps a speed for each site, ramps the speed up slowly and reminds you to watch a video later. Open the widget's Playback tab and find Automation. None of it needs an account.
Settings, Video Features tab, Playback automation lists your blocked and allowed sites, your site speeds and your reminders, with Remove beside each one.
Block autoplay
Press Block autoplay here and videos on this site wait until you press play. A held video shows "Autoplay blocked — press play to watch".
To block it on every site, turn on Block autoplay everywhere in Settings and add the sites you want to keep under Sites where autoplay is allowed. Tick Tell me when a blocked video is ready for a notice when a held video in a hidden tab is ready to play.
Keep a speed for a site
Set the speed you like, then press Keep 1.5x on this site (the button shows your current speed). Videos on that site now start at it. A speed the extension remembers for one video or one playlist still wins.
Speed ramp
A speed ramp raises the speed bit by bit while the video plays. Pick where it ends, from 1.25x to 2.5x, and how long it takes, from 5 to 30 minutes, then press Start. It moves in 0.1x steps. Press Stop to end it.
Remind me to watch this
Press Remind me to watch this and pick In 1 hour, Tonight 20:00, Tomorrow 08:00 or Pick a date and time…, then Repeat it Once, Daily or Weekly, and press Set. A browser notification arrives at that time. Click it to open the video. On YouTube it opens at the moment you saved. You can have up to 50 reminders at a time.
One video at a time
In Settings, Video Features tab, turn on Pause videos in other tabs when one starts. When a video starts, videos playing in your other tabs of this browser pause. It is off until you turn it on, and it needs no account.
Up next from Watch Later
This one needs a connected account. It starts off. In Settings, Video Features tab, turn on Play my Watch Later in order and pick a Countdown of 5, 10 or 15 seconds. When a video ends, a card over it counts down to the next video in your Watch Later list, or to the first one when the video you finished is not in the list, with Play now and Cancel. After the last video, nothing plays. Replaying or seeking back cancels it, and a looping video never ends, so it never moves on.
Resume from another device
With Remember Playback Position on, a connected account and Watch History turned on, the extension can pick up where another device stopped. It asks: "You got to 12:40 on another device. Resume?" It does this only when this browser has no saved position of its own, and not near the very end of the video.
Shortcuts
"Block autoplay on this site" and "Start or stop the speed ramp" start with no key. Give them one in Change a shortcut.
Next: Watch limits and Focus Mode.