Opposite "UE to Rigify" worflow

So I am wondering if someone who has gone through the workflow (showcased in the Blender to Unreal livestreams) has also tried going in the opposite direction or from the middle. Maybe this comes from me not completely understanding what UE to Rigify does exactly but here goes.

The workflow demo starts with the UE Mannequin imported and then basically its bones being converted/mapped to a Rigify rig and then back to UE, while retaining the UE skeleton.

  1. import Mannequin with weighted armature
  2. run UE to Rigify to create a rig
  3. bake rig animation to UE skeleton animation

Now since the addon can bake animation from the rig to the UE skeleton (since it has it as a template), can you use it to do just that? Using a custom character that you rig with Rigify and then just convert that the Unreal skeleton?

Basically I though since the template (mapping Rigify <-> UE Skeleton) exists, then anything you rig with Rigify could be imported to UE with the UE Skeleton.