Yes the Prefitter-CR2 is one way to go. Thank you for mentioning,

There is also a content development kit for PE. It is available on CGBytes and it has an injection morph for V4 to correct the shape to PE and mannequins you can use as source for joint copy and morph copy. It is still in Beta and officially for the Early Edition of PE, but it works fine for the One and OneX versions. Personally I use a combination of the Prefitter for geometry transform and the mannequins as donor for rig and PE morphs.