Merging animation graphs in Mutable

We are using the Mutable plugin, and it works well and as intended, with the exception of one point.
We have spitted up our gear and armor for characters into separate skeletal meshes. With Mutable we are able to merge the skeletal meshes into one and the same at runtime. Everything works really well with physics assets, cloth simulation, materials, etc. However when we have modular skeletal meshes that use separate post process ABPs, we have not been able to get one merged ABP to use for the merged skeletal mesh that still deforms all the joints from all the individual modular pieces. In the official documentation Mutable Overview it is stated that it “Combines animation graphs of multiple parts” but we can’t get that to work. Is there any additional documentation about this? Or can someone point us in the right direction of what to do?