Allow change button adding direction

[lyndametref]

Is your feature request related to a problem? Please describe:

I am playing with a G13, which layer (3 rows with 7/7/3 buttons) currently I have 3 bars as below:

but I would like to be able to have the same layout in one single bar. When trying to have a bar with 18 buttons and 7 columns I obtain the following:

Describe the solution you'd like to see implemented:

I would like to be able to choose the direction in which the bar is growing: top->bottom in the above example (currently bottom -> top)

Describe alternatives you've considered:

Multiple bars works, but each bar must be configured separately event if they have the exact same configuration which is not optimal