url class/site filter for tabs

A filter for watcher tabs could allow threads and watcher urls to be sorted automatically for specific tabs as the user wants.
Setting for example the watcher tab to 4chan should drop the url into that tab and not others..

By default the watcher tab should accept everything like it does now.
Having the option to filter could enable better tab sorting automatically without requiring to be in a specific tab..

This could also be re-used for the gallery tab in the same manner if wanted..

And global option for new tabs to either stay unfiltered or create a new filtered tab for the site could be wanted.

EDIT:
Editing this to be more general and open ended.

An URL Class Filter for tabs in general, Allowing a tab to be connected and tied to an URL class when open.
Allowing users to drop an url of any kind that URL Classes support and drops it into the correct tab.

This could easily done with Watcher tabs first as they support urls.
Galleries will be dificult as it requires to pull the query from the URL to work that way.

Global option for new, unfiltered urls to either make a new unfiltered tab or a new filtered tab for that site specifically.

Start by reviewing the existing URL Class handling and watcher-tab behavior described in the issue. Define the scope of how tabs connect to URL classes, including default handling for unfiltered URLs; done should include routing supported URLs to the appropriate filtered tab without removing the current default behavior.