I have a number of different body shapes created using the Pose Morph tag.
Now I have clothing modeled around the base shape, but I would like to transfer the various body shapes to the clothing.
Is this doable in Cinema 4D? (I primarily use R19 if that matters).
This is not my area of expertise, but I remember seeing this done with deformers the question is which ones?
I would try the surface deformer or the mesh deformer. You can always use the correction deformer to fix localised issues for the poses.
I’m assuming you didn’t use a character rig to create the poses otherwise use that. Depending on how well the deformers work you may have to consider rigging the clothing with a character rig to match your poses.
It might be easier to start from scratch and use a character rig to pose the base model then use that rig to pose the clothing.