Until the feature is implemented we have been updating the internal tabs table to set our desired widget layout. We tried using a reference user and linking to that users tabs but with user authentication enabled the tabs of other users are restricted from view.
Ideally it would be great if:
->Admins could view/modify the name/layout of the default tabs.
->Admins could also disable which tabs were created by default for new users, and the order of the default tabs (similar to how custom actions are ordered).
->Admins were able to create a tab that is visible to all users, with the option of setting the tab as read-only (so users cannot alter the widget layout).
This would allow:
X number of default user editable tabs + X number of editable/read-only tabs set by admin.