This idea is about reduce space usage. Instead of putting tabs above (or below) urlbar, integrate it, such like search engines. When user click on Awesomebar, pinned tabs could been displayed in one line (at top of menu) and not pinned tabs (with labels) line by line below pinned. When user type character, we could hide tabs or additionally search in tabs. I know, that’s request to click one more time, so maybe make this idea optional.
maybe you can sketch your idea, to make it easier to understand?
P Means pined tab. We will place tabs at top of awesomaber menu. You can restrict size of this area and add scrollbars.
The idea allows to remove tab panel to gain additional space. Of course, it allow also to not place tabs at title bar, so we omit many problems with it, like moving window/dragging tabs exclusion, etc.
It is also more intuitive: user don’t have to known what tabs are - he/she only opens awesomebar just like navigating per pages.
Edit: You could rename tabs to “read in near future”.
Thanks for your post.
This seems like a good idea on the addons space, if you can get someone to implement your idea on an addon we can see how many people find this useful 
Cheers.