So it would be great to have something like 'Tabbed ContentBox' or 'Tabbed Container' allowing user to save space when needed, and i've found myselft in those situations. Frankly while there's a 'ContentBox' element in the set i personally don't find it too much useful, but tabbed solution would be more helpful in building practical apps.
I see its appearance like so: tabs can be configured by user horizontally(default) and - preferrably - vertically too. Alignments: left(default), center, right. Active tab (bolded to stand out) can have configuration for bgColor and also something like tabChanged event assigned to trigger other things.
Hope in some future versions similar UI enhancement elements will be added

Thank you