Instead of showing just a line with both horizontal and vertical tab bars when moving a window back into another window, make them dynamic.
Vertical tabs.
Horizontal tabs.
It should show like this instead:
So in essence, what I want is that the tabs make space for the new tab instead of merely just placing a line.
This is much more better as for very large tab collections, it is much easier to see where your tab is instead of looking for a tiny blue line which may be difficult to see for color blind users.