To answer my own question: when I move the control channels from the hands into the body, pose the hand using those dials and then save as a hand pose, the .hd2 file doesn't capture any of my settings at all. So from my limited experiments, it actually seems that the way phantom3D originally set up these dials is what works best for saving and restoring hand poses.

-- I'm not mad at you, just Westphalian.