I had a pre-built a while back that came with a spacebar not too unlike this - the smoothing was less obvious but same theory, with the middle having the most rounding, slowly sharpening into a rounded corner at the ends. It’s not a good looking set (first round of caps that came on the Anne Pro 2), but man did I enjoy using that spacebar - only one I never felt the need to flip, and it’s because that harsh corner just isn’t there.
I’ll have to keep my eye on this one… since HSA apparently never actually happened and OSA is… iffy… well, maybe these folks will nail it!