on a desktop I end up reading reddit (when I do) with furious amounts of middle clicking for new tabs, so I wonder how you'll work with that usage model (it's why I never use reddit on a phone...)
the problem is that users don't like that nowadays, they like it managed by the application lest they get some kind of too-many-open-windows fatigue (though I believe that's caused by WM failings/deficiencies, myself)
I suppose you should treat tabs like they work on Web; they can contain any view; but then you get to the problem of toolbars....
A pity because it's detached hosting with no functionality and no userbase, which makes it harder for users and contributors to interact with the project, and no clean takedown policy, which lessens trust to it. And it was probably down for noticeable time so I've considered it dead.