Thank you for your cascade of comments, Vladyslav. (560 words of comments on 132 words of a post is impressive! No wonder that the manual for Tabs Outliner is so convoluted... :) )

A few brief points in reply:

 everything the original author mention is true, but the tool is not aimed meantime to cover this case, it is a bigger and more ambitious goal

Thank you for agreeing with me. What can this goal for a tab management extension be other than tab management?

 And where do you find the tags in original browser bookmarks?

I add them to the bookmark title, prefixed with #. I can then search for them either in Google address bar (omnibox) or in the Bookmarks tab.

 But the primary idea is not to organize anything. I never be able to do so. Nor with bookmarks, nor with the anything else. The primary idea to be some sort of free form notepad, and to deal with a problem of hundreds open tabs - to easily close them any moment you wish. And then, then next goal is not to organize all of this shit, but delete! But not trash all at once, but as selectively and timely as you wish. That is why drag and drop is so important, and the idea is that everything can be dragged on anything, that is why the delete screencast is one of the 2 screencast i post in Quick Start section.

Organisation should be inherent in an extension called "Outliner". Tabs Outliner makes it easy to close tabs. But it does not render them useful for the future. And Tabs Outliner causes laborious and unnecessary work by sooner or later forcing the user to manually curate a long list of ever more duplicate tabs. This is all the more tedious since the only available tool is drag and drop.

So yes, for organizing, collecting and so on you will be better served with some other tool. When you find one please report - it is very interesting. No one is work for me despite i use dozen of them.

In case you missed it in my 132-word long post: "Using Tabs Outliner for some time now, it ultimately made me look back to the potential of using Chrome's default bookmarks/search and tagging for tab management. The key here is not to let tabs accumulate, but rather save them as bookmarks and tag them, or even add them as todos in a task manager."

Chrome Version 25.0.1364.172

Tried again by Ctrl-S. "Save HTML only" did not work (file produced only contains a separator line). "Save as Complete page" did work this time around. 

Sorry for the false alarm and many thanks for the prompt reply!

By the way, I have been trying out Tabs Outliner for a couple of days now and I like it more and more. Have gone down from 290 open tabs to 100 tabs then to 14 tabs, Chrome is responsive again, and my browsing feels much more organised and comfortable.

Many thanks again!

Thank you very much for both replying so fast and dispelling my fears.