Changing just the the front of the lower increases the separation of the upper and lower links at the frame. For the rear since you are raising the mounting point you have to also raise the upper arm mount so as to not decrease the link separation of the links on the axle. One of the things that the geometry correction does is to actually increase the link separation which helps with the loading of the upper links since we are moving the lower closer to the axle centerline.
OK that makes sense. Thanks.