There’s no scaling going on anywhere, I’m afraid, not in Maya, nor in UE4.
I just completely remade my growth mesh from scratch, which resulted in… exactly the same thing. I’m going to try one more thing, which is altering the retargetting in the skeleton from Skeleton to Animation in persona, to see if that does anything.
If – doesn’t work! then I dont know that will.
EDIT: - And that didn’t work either. So the only option remains remaking the rig, I suppose.