[rgoulter]

> Perhaps the Enter key could be in the middle, ... Yes, such keyboards exist.

As well as enter/backspace/delete, it's also useful to have esc/tab near spacebar. https://github.com/manna-harbour/miryoku

e.g. A popular off-the-shelf keyboard which supports this layout https://www.zsa.io/moonlander/

> ...below the space bar

Well. Then you'd need to move your hands, or stretch your fingers a bit. It's better to have a smaller spacebar key, to allow for extra keys.