I was supposed to learn touch-typing in school, but all I learned was how to game the system. To this day I still type with pretty much only index and middle fingers, even the space bar.
I don't feel particularly restricted by my _maybe_ slower typing with more frequent mistakes due to looking at the keyboard. Like you said, my job is engineering, not typing.
right, i forgot about the looking at the keyboard part. that is a distraction, but in fact, i have been doing this for so long that i can type with just index fingers without looking at the keyboard. seriously, i am am trying this right now, and i am astonished how few mistakes i am making. it does feel awkward because i am not used to typing this way but apparently my muscle memory is good enough...
I don't feel particularly restricted by my _maybe_ slower typing with more frequent mistakes due to looking at the keyboard. Like you said, my job is engineering, not typing.