Earlier quoted context omitted.
If you re-arrange the keyboard into a shape according to human hand ergonomics, you can easily fit a number row that is easy to reach without making typos. See kinesis advantage. It's hard to imagine how requiring me to press two different keys for the same effect would increase speed and reduce typos. I suspect the effect is completely opposite. (Shift is painful enough and I hate typing camelcase code) Number keys…
The further keys on a sculpted Kinesis keyboard are angled the wrong way for comfortable typing (this is an unfortunate artifact of their curved PCB technology combined with lack of first-principles analysis by the designers). You want the switch axis to remain perpendicular to the hand, because flexing the proximal joint of the finger is the way people press keys, and using the whole hand to stab at further keys the…
I've never found that to be the case. For me, layers (and modifiers in general) have always been slower and more error prone.
Also, I find the number row on the kinesis quite comfortable. I have yet to find a comparable keyboard in that regard.