can create corrective shape together instead of one by one
All the raw corrective shapes should be named in the convention: nameofjoint_rotateaxis_rotatedegree
for example, if the blendshape deformer is 1 when rotate bn_jaw on x axis of 50 degree, the corrective mesh should be named as bn_jaw_x_50
for negative degrees, use bn_jaw_x_n50
First, select all your corrective meshes, then select the binded mesh, then select the root joint. All the resulted mesh will be created and under a new group