Hello!
I may be misunderstanding/misinterpreting your situation (if so I apologize), but if you go to More > All in the tabs on the right hand side of your TiddlyWiki you'll see, if I'm reading the contents correctly, individual Tiddler's for each of your bookmarks.
As example:
The first link under the TiddlyWiki How To section can also be found as an individual Tiddler here:
https://brainfck.org/#Google Groups Thread on exporting/rendering Tiddlywiki instances
To me the plugin seems to make and organize the individual tiddlers, as bookmarks, for you and then displays them in summary view tiddler's based on your settings.
You can also go to More > Tags and scroll down to the green TiddlyWiki tag and when you click on it you can see all the individual tiddlers that are displayed in the summary bookmark view of the TiddlyWiki page you linked above.
If you are asking if the above approach (an individual tiddler per link with summary pages) is better or worse than a manual page with a bunch of links you update as you find them then I would say, based on consideration for the workflow involved, quality of life interaction/steps, and also the fact that many users here have stated they have massive tiddlywiki's with little performance hit, that I would stick with what you have and not be too concern with the size.
So far the only concern I've noted on here, regarding TiddlyWiki size, is when a Tiddler was renamed and a plugin had to go back and review an index of all the tiddler's to see if it needed to update any of them. But that seemed to be a unique case.
Again, sorry if I misunderstood your question/situation.
DM