I personally don't import camera positions, it's just too easy for fixed cameras (and their lenses) to get gradually off their previously calibrated positions. Also, if you are using multicam rig with good lighting and some of your cams fail to align, it _usually_ means your photos are not sharp enough, or your cams are spread out too far etc. In case of really pale skin/featureless subject, you can go to 'Tools/Export/Export_Cameras', save your 'sphere' camera setup and then load it ('Tools Import\Import_Cameras' when you switch to your 'face' setup.
-Andrew