BTW a common ergonomics misconception is since our fingers are rounded concave touch or grip areas will be more comfortable since it follows the rounded topography of the fingers, exactly the opposite is true.
Our hands has developed/designed to grip sticks, stones and varied shaped objects. And there's simple physics...
I also can't use any other device but the simplest, most standard, compact and light plastic mouse. my current one doesn't even have a brand on it. I handle it with the tips of my fingers with minimum effort. Years ago I suffered a lot of wrist and finger pains from mice I had to fight with for long hours, I moved from it to Wacom tablet and pen for several years (as a total replacement for a mouse, not just for creative work), it also operates with no efforts so never caused me pain and fatigue, even though the pen buttons were always a bit tricky to operate. I used to set the tablet's "active area" to about 9x7cm (something at the size of a track pad or even smaller) which enabled very quick and easy cover of the screen with reasonable accuracy. It may have been that I lost the tablet's pen or gave it to someone one day, I'm with the most humble mouse out there since.
I hope it's ok (remove if not) to ride on this topic, asking the same question about this g' I came up with while working on a new typeface (and another one). It is an hybridisation of two and one stories g'. Do you know any? What do you think about it?