I also don't experience any noticeable torsion at the elbow. Putting my hands in front of my chest is a perfectly relaxed posture for me. Typing is not that different from writing in terms of where my arms and hands are (other than the two-handedness).

That said, I do move around a lot instead of keeping my hands always on keyboard, so maybe that's why I don't experience the typical fatigue at joints associated with keyboard usage.