I think it would be more productive to have a individual panel just for code. Parallel and fixed (or abble to pin somewhere) like the image below (it’s a quick sketch but you get the idea), and it could be stretched as far as you want. Also, the 3 language panels would be collapsable too.
Even if the layout area gets smaller, it’s enough to preview, and there are times when we mainly want to code.
Sometimes we alternate between elements a lot, it’s hard to keep going back and fw between panels.
For full control it could be a separate window.
