When using a modular pawn, how do you set morph targets?

I’ve used the modular pawn class in the following link to create a character.

I have a head mesh as the master, and body and legs meshes as the two slaves. So each mesh is exported with the full skeleton but only has a mesh on the parts that it should have. There is a morph target I want to use on the body of my character which clenches the hands into fists. However, I can’t seem to interact with this morph target no matter how I go about trying it. I have tried exporting all of the morph targets on each of the three meshes (though I’m confident this is not correct), and I’ve tried only exporting the relevant morph targets on each mesh. When actually trying to set the morph target, I would assume that I should try to set it through the head since it’s the master, even though the morph target I want is on the body. That doesn’t work, and neither does trying to access it directly through the body mesh. If I switch the master mesh to be the body rather than the head, then I can interact with the morph target just fine, but I can’t interact with morph targets on the head.

I think this may be a bug with UE4, but I’m not certain. Does anyone have any experience with morph targets on modular characters?

Any information on this at all? Modular characters and morph targets? Anyone?