Control Rig - how to filter out animation axes?

Hi everyone, I’m using control Rig making an auto-clavicle setup. I have it working using an Aim node but the clavicle is rolling. I only want it to pitch and yaw. I tried converting quat to euler and rotator to remove the specific roll axis but it seems to remove pitch. Naturally, I tried other axes instead but the result is the same. How can I limit the rotation of the bone? The Aim node seems to even override the limits set on the control.