I’ll second that question. I am currently at the same stage, I am trying to define a custom pose in my UE4 → MH retargeter, it somehow works, but it’s only a rough guesstimate with no fully satisfying results. Being able to copy / import / export a pose would be the logical step to get an accurate reference pose for MHs. But to date, it seems that pose edition in the rig retargeter is too feature-limited. If I’m wrong, I would be grateful for someone to explain.