Finally looked for something like this, I clearly should have done so much sooner.

would be a very useful tool but unfortunately it can only be used for your own playlist not for every YT generated mixes/playlists

does what it says

Does what it says on the tin. Fast and minimalist.

Almost perfect.
Since the button is dark it's invisible in dark mode. We need a white button.

Finally! I've been wanting this for so long to deal with my thick as fuck watch-later list.

Great feature! After many years of YouTube removing this very helpful function, we can finally have it on Firefox. Thank you so much for your support!