Toggle Composer layout to position Editor and Preview as top-bottom instead of left-right

I was playing with a wide table earlier, and sadly it started to fall off the screen(even with full screen editor and a very wide monitor). The issue is that the preview always takes up only half of the left-right real estate.

I played around with the positioning in the browser session, and after moving the preview window and wrapper my composer looked like this:

This is great when working with wider tables as you get immediate feedback on your changes. And whilst I could also utilise the table editor, this layout just made the whole topic easier to edit.

I’m wondering if there’s ever been something like this considered before?