Difference between ControlRig and AnimBP IK nodes

I found that same IK nodes (FABRIK and CCDIK) work differently in Control Rig and AnimBP:

ControlRig’s IK is stretching last bone Translate to Effector, while in AnimBP’s IK bones do not stretch.
Does anybody know what’s the reason for that behaviour or how to fix Control Rig’s IK stretching?

but its not the only difference.

Control rig runs after the frame is composited. And I think also after physics.

Also the IK nodes should have an option to allow bones to stretch or not. Could be one has it toggled on…