Not having "Margot for v3" I can only guess at what is going on.

One possibility comes to mind. It's a bit hard to explain, but I'll try.

First we have to understand a little of how a FBM works. Put simply, when I make a FBM, Poser looks at all the individual morph (targetGeom) channels in the figure, if a channel has a non-zero value it is slaved to the master FMB (valueParm) channel in the BODY, if its value is zero it is not slaved (is not included as part of the FBM).

Another fact, you can't spawn a FBM from a FBM. If you apply A FBM, then try to make another FMB, the new FBM does nothing. A FBM can only be made if you first set the individual morphs in the individual body parts.

Now what might be happening is that the "Margot for v3" character is seting values for the head morphs directly in the individual channels, but is using a FBM dial in the BODY to set the rest of the morphs in other body parts. Another factor that may come into play is that some character injections use scale channels, and scale channels won't be included in a FBM.

I'm just guessing that this is the problem, without seeing all the files involved it's hard to say for sure.

I can understand that you are feeling frustrated, I think anyone who uses Poser ends up feeling frustrated a lot of the time, but perhaps it's a little unfair to blame Wardrobe Wizard. In your first post you seem to be saying a FBM you made in Poser is not working, so shouldn't you blame Poser?