If it uses the same skeleton as default UE4 characters, only with altered proportions, you should be able to copy the standard profile and simply make adjustments to scales of certain bones.
Different types of bones have different behavior and options.
Something different, say with 3 arms and 4 legs, should still be doable without code modification. You would only need to make a new profile assets and fill out the parameters, and maybe use custom bone meshes.
As long as the mesh’s skeleton is “anatomical”(meaning the joints are where you expect them to be) the plugin should work in the majority of cases with no modification.
I intend on documenting the C++ as thoroughly as I can.
In short, the plugin isn’t limited to human characters at all, those are just the only meshes I can include atm. I’m going to grab some more items from the marketplace and make some examples of using it with nonhuman characters soon. Depending on similarity to humans, you won’t need a full set of alternate bones. Using a custom skull will probably be the most common bone replacement.