VRIKCalibration doesn't actually do that. It only calibrates the general scale of the avatar.
But if you wish to adjust limb proportions, you can do so my adjusting the Arm Length Mlp in the arm settings and Leg Length Mlp in the leg settings. The automatic stretching feature also helps with masking problems related to limb proportions. You can enable that by going to the "VRIK (Basic)" scene and copying the "Stretch Curve" over from the Pilot to you own avatar.