Switch layers can hold bones. Perhaps you didn't know. (selgin put the ear 
). It is described int AS/Moho help but so few people read completely te tutorial or the help. Taken from Moho help:
More accurately, a switch layer is a bone layer, just a specialized one. If you add bones to a switch layer, you can use them (for example) to change the shape of a mouth as it speaks, bending it into a smile or a frown.
Sometime switch layers hold vector layers controlled by bones from the swtich layers. Sometime (more often than you can imagine) verctors layers inside switch layers are quite different between them. Not only the shape, also the movement.So
¿How can we switch ALSO the bones in a swtich layer to make them consistent with just the new vetor layer selected?The main example are legs. Legs facing right and facing left.
Solution: Duplicate the sekeleton as many times as you need.In the example I have two pairs of legs for each position. One looking right and other looking left. You can select them in any combination and can be animated by their own bones.
There is only a precaution. The links of every bone must be correct. I mean that in this example when you create the femur for the second leg you have to be sure that no bone is selected. Then it is like a new skeleton just created in that switch layer. Anyway you can always reparent the bones after. But remind to have two independent sub- skeletons for each orientation.
Hope it helps you.
Genete.
