I love workbench - its absolutely great, so why not make it even better. Right now a double-click on the list of repos on the left is required to open multiple repo tabs. Then one can switch between tabs with a single click. Some functionality is duplicated. (list on the left requires a double click, while tab-list requires a single-click).
Get rid of horizontal tabs bar, to save space. Handle single-click on the repo list on the left to switch between repos.