So cool that they're using the QMK firmware and open hardware. They also include a split space-bar, taking one of your digits "off the bench" :) [1] I made a crazy ergonomic keyboard, but I think the most useful things in practice are to have a keyboard be programmable and to have multiple keys for the thumbs to use.

Backspace is one of the top three most used keys for common computer usage, putting it on the thumb is a huge win over the corner to be used with the pinky (or a Shift, Control, Enter, etc.). The layout is otherwise fairly conservative with dedicated function keys, arrow keys, and navigation keys (albeit in a non-standard cluster).

[1] see key layout and mapping: http://www.keyboard-layout-editor.com/#/gists/8ec5e9026d616e...