Very nice idea and works smoothly on Windows. It works perfectly on Linux with KDE. However, on Gnome, the keys do not have a good response at all, and after a little investigation, I saw that it is probably due to my distribution (Debian buster). The price is high compared to what it should offer. It is probably not the best for programming, especially for those who use VisualStudio, as the F11 and F12 keys are coupled with the F1 and F2 keys and only work by pressing the Function key. The same goes for Shift+Insert. The positives are the small-slim-factor and the very small weight. Also, you get used to it quite easily.

Update 28-02-2022:
After a month of use, I can now confidently say the following:
1) The idea of ergonomics is very good but fails due to the very poor responsiveness of the keys. You literally have to hit them. The same situation occurs on Windows 10 and Linux (KDE+Gnome).
2) The USB cables that connect the two halves frequently disconnect no matter how careful you are. Also, due to the increased wiring, the useful space gained from its small size is lost because you have to be careful not to move the cables.
3) I missed the essential Function keys F11 and F12, and I couldn't get used to pressing Fn key+F1, F2 every time. The same applies to the Home, End, PgUp, PgDown keys. In short, it is not suitable for programming unless you excessively use the mouse for everything.
4) It is overly expensive for what it ultimately offers.

Unfortunately, too good to be true