I wouldn't say they're like, "typing on air". More like, "typing with magnets" 👍
I'm currently working on making the Riskeyboard 70 PCB and the AKU PCBs available for order and when that happens I'll also make the OpenSCAD .scad files and firmware available for download (all open source). In the mean time here's a rundown on some of my keyboard and switch features: