I’ve been playing around with this setup a bit. Previously, I’d mostly have my left hand on the keyboard, right hand on the trackpad or mouse.
Now I find myself leaning back, and having both hands on the external numpad. This is actually very convenient. Not least of all because it’s a different posture and feeling than my day-to-day work that also happens at the same desk.
The color correction keys are really useful, even though the leftmost axis (red-cyan) does not work (the “red” slider in color calibration CAT16 operates in magenta-green, like the second axis). It usually just takes a few keystrokes to get any minor color cast equalized.
The top row I have assigned to lift, brightness, gain in AgX, together with the rotary dial. In fact, I’ve set the rotary dial to operate as a mouse scroll wheel, which is unexpectedly useful.
The bottom black/grey/white keys, I’ve assigned to AgX toe power, exposure, and shoulder power. These were intended to operate like the colored keys, so as opposing pairs of up/down keys that you hit multiple times for bigger adjustments. But this feels cumbersome, I’ll likely remap them to operate with the scroll wheel instead. This would free the bottom row for Tone EQ shadows, contrast, highlights, which seems better.
Configuration is a bit annoying, since you can change both, the key bindings for the numpad, and the shortcuts in darktable. It’s not always obvious which one is better to change. At least the numpad can be configured through VIA in the browser (with webUSB), which is reasonably simple. Not that the docs would tell you that, it instead misleads you into a procedure that does not work.
Still, overall, this has turned out very useful. Not necessarily faster or better than my old mouse-and-keyboard system, but more tactile and fun.