RFE: Vertical Tabs...
Might come in handy.
The ability to switch (particular) windows from horizontal to vertical tabs.
Depending... what you're doing... might very well come in hand.
running out of space on the (horizontal) tabbar,
having a vertical layout gives you more tabs in the same space
at a particular window size, lets see...
7 tabs horizontal, & you can fit 14 vertical...
Earlier, [Suggestion] Tabs Improvements