Add option to disable 3-column mode.
Feature request
I would like an option to disable the 3-column mode. When I resize my browser window wider than ~1280px, the notifications section moves from under the sidebar to a new column. Attempting to undo the changes with CSS isn't possible as the page gets modified when the switch occurs, so the closest one can get is a page without any notifications.
An option to disable 3-column mode or pick a preferred mode (2-column, 3-column, or automatic) would satisfy me. I would also be happy with changing the behavior so as to not modified the page's HTML on resize thus allowing custom CSS to change the mode too.