Created one Control Rig for the character rig setup and a second for procedural crouching which I blended additively into the character run animation within the Animation Blueprint. I used jiggle and chain dynamics in the rig to create fun and more intuitive control. I also used spring interpolation in the crouch animation for a smoother feel.

Using one Control Rig was breaking my main animation. I discovered that creating a second was a way to blend in new animation without overriding the original behavior.

At one point I wanted to modify my skinned character in Maya and found that I could copy my Control Rig to my newly imported character.