Animation Retargeter not aligning properly

So the situation: I am attempting to separate my character into different skeletons so that I can swap out physics components that either aren’t necessary all the time or behave differently (Hair styles and long coats etc). I’m using the IK retargeter in conjunction with the “Retarget Pose from Model” node in the individual SKmesh’s anim blueprints.

THE ISSUE is that whilst it technically works, I’m running into clipping issues in UE that I’m not running into in the original blender file. To me, it looks like they’re not quite alighning as 1-1 as it should do.

UE:

Blender

The green shawl is a couple CM above where it should be on the model, which has led to clipping in the armpit/upper arm area.

The green shawl in this instance uses a skeleton that is almost identical to the core main body except it has bones for physics in its length, no head and no fingers.

I’ve tried fiddling with the target chain’s IK and FK settings but it only creates new and fascinating other clipping issues that again did not exist in the original blender file or its weights. I might be doing it wrong though.

Does anyone know what could be causing this?