You just have to click Visualize Grid, and then re-order the slot locations numerically in the order you want
So instead of:
1|2|3
-------
4|5|6
-------
7|8|9
Rearrange it to something like:
1|4|7
--------
2|5|8
--------
3|6|9
So instead of:
1|2|3
-------
4|5|6
-------
7|8|9
Rearrange it to something like:
1|4|7
--------
2|5|8
--------
3|6|9