Thanks, ClockworkOcean, that does look promising!
At the moment, I’m doing foot IK (based on Alessandro’s tutorial (http://unrealdevelop.byethost11.com/2016/11/15/ik-feet-placement-setup/) in a combination of my Anim and Character BPs, and my partial physical animation simulation entirely in my Character BP (see below), so I’m not sure how I would incorporate the Mesh Space Ref Pose into the process. I’ve also included a screenshot of my AnimBP.
When I substitute the Mesh Space Ref Pose for the cached Idle, the character reverts to T-pose while not moving. When in T-pose, the distortion problem is fixed, but returns as soon as the character begins moving again 