I found that I could hack a purchased mocap from the Platform and Carriage pack to produce a screentest for my script (even if not the final render).
Following some great advice found somewhere on the forum, I was able to use Sample Optimized on the motion in order to remove the arm motion of looking at one's wristwatch (that kind of watch was not available in 1860).
The result is really appreciated on the Facebook page for Professional Animators, but someone could tell that this is mocap, not keyframed animation.
So my question is: if I had erased a lot more of the motion markers for all the body parts, to isolate classic keyframes, would iClone automatically tween them to produce more streamlined motions?
Animating now to life itself --Walt Whitman