Setting bodies physics blend weight, blends an animation with physics simulation but does not update the collision bodies to match as is expected, instead the collision bodies are at their fully simulated positions.
Open PhysicalAnimation in ContentExamples.
Play and enter PXVIS COLLISION console cmd.
Regarding the first three mannequins:
Adjust the blend slider.
Note how the collision bodies are now at their fully simulated positions, regardless of the blend strength.
There's no existing public thread on this issue, so head over toAnswerHub just mention UE-72912 in the post.