> The labeling feature would be handier if I could tag/label sets of tabs.
You can! Instead of tagging each tab, you can rename the containing window's "Window" text, as if it was a manilla folder. Windows can also be contained in (named) Groups, allowing for hierarchical categories. Bottom-up tags can be accomplished by adding a note as a tag (I like using #hashtags to differentiate from plain text). In terms of retrievability, Ctrl+F doesn't discriminate!
> the clean-out problem: it's a goddamned pain in the ass to go and sort through the stuff you've tossed in there and clean out the junk.
I forgot to mention a workflow video for that: https://www.youtube.com/watch?v=VvlK1ttZ3dI
The dev has mentioned elsewhere that this extension is not (yet) designed to organize, but rather to get a handle on the tens/hundreds/thousands of tabs one may have open. It's done it so well that I have a lot of ad-hoc 'fuzzy' categories and random notes inside my outline I would love to be able to manipulate and build into a grand scheme or other. To use an analogy, it's like a great grafter/sieve to separate the wheat from the chaff, but there's no cooking oven.