It's often useful to place a collider between the hip and spine bone, to prevent (for example) a tail from clipping through the body. Before IK 2.0, this could be done by setting a capsule collider of an appropriate size; however, now with "lock both" mode, the hip-spine length can vary, resulting in the collider extending outside the intended area.. Being able to specify the start and end points of the capsule (instead of an explicit height) would help resolve this issue.