After a bunch more testing, there is in fact a way to have multiple crosses on the same limb.
1) Follow above guide for a single crossing limb segment on the arm.
2) To create the next crossing, create the next part of the limb you wish to have asymmetrically. Then ctrl it onto the right side. do the hand trick, pull the hand across, and then remove the hand.
3) The limb will not duplicate! You cannot yet save :/
4) Repeat the process with the exact same limb and place it on the other side (so you have identical extra bits on either side from the original crossing limb, but they are not actually both the same)
5) Yay! You can save now. Somehow this tricks the game into thinking the other half of the limb is there. Unfortunately, if you stick a hand on one side, it will float over the other limb, and not be connected. Continue for how to fix this!
1)Create two more identical (or not, at this point) asymmetric limbs, with the desired features, weapons, arms, feet.
2) Place one on either side.
3)Ta-da!
So the method a few posts up is always used for the first crossing (well, this could be used for the first if you wished, as far as I know), and then this method of creating both sides separately is required for any other crossings wanted, and for the final terminations of the limbs if more than one crossing is used.
Edit: Example

The arms cross once over the chest and a second time out in front, and there is a different hand on either side. They could be the same, if one wished, giving the appearance that it is not asymmetric.
If all this is too hard to follow I may post a visual guide sometime this week, because this builds on all the other techniques and is more complex.