Vertical Hotbar? Or 2 rows / 6 six buttons?

[Kelbar]

Yo!

What do i have to change to make one of the 3/4-size Hotbars vertical?

or have it splitin 2 rows of 6 like
1 2
3 4
5 6
7 8
9 10
11 12

so I can have 2 of them on the side of the screen?