Just learned about the corner part today. Might have to use that in the future.
I really meant 4 vertical panes. Most of the time I want the height but not the width.
Where I use it a lot is when I have something on the main monitor and want references on the second monitor. Like, during our D&D games I want Roll20 open full on the main monitor, discord on half of the side monitor, and the browser on the other half of the side monitor. With multiple monitors it is easy as you can just drag to the edge of the screen (or use the keyboard shortcut as you mentioned).