Hey Kristiamo,
did you have any progress on this since you asked this question?
I am currently working on blending from ragdoll to animation and I am facing the same problems.
I thought maybe detaching the mesh from the capsule → then move the capsule to the pelvis → then attach again (keep world position) → blend from physics to animatino and blend mesh position root back to capsule with the same timeline as the physics/animation blend.
Is this the right way to do it or do you have any other ideas?
Last question: How can you make the bones visible while playing like in your video?
Regards, Joey
EDIT:
I made progress on this and also found a bug (I think): You see the bug report here: (Helpful screenshot of blueprint inside on how to get out of ragdoll)