Having just installed this, it appears to work well, letting me choose the sort order like usual and then hitting the new, purple Play All button to create a playlist in that order. I'll update if I have any issues, but so far, this is exactly what I wanted.

Well, you can see my original review below but it broke after one use...so I might have to make the add on after all (sigh).

Thanks for trying I suppose.
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I was going to make this add-on and was super relieved when it already existed. I don't know why there are reviews saying it doesn't work for some people. I doubt they are lying, but it certainly works for me. I would recommend anyone having trouble make sure that their mozilla is up to date, because a "Play All (Latest)" buttons should appear on the home screen of youtuber that creates a list of all their videos when clicked and brings you to their Unlisted list. No complaints, it works for me at least. If that changes, I'll revise. -

It is a dud recommended by Google AI.
Not even active on the page.
I have wasted 30 minutes of my time trying to make it work.

As advertised, works well.

Works well.

Looks good and works well.

It's working.