IK / FABRIK blueprint tutorial for proper foot placement with capsule collision

You should be able to manipulate the foot bone in world space. You need to combine 3 rotators: first, you need to align the foot’s yaw to the rotation of the player capsule, then offset that yaw to match the proper yaw of the idle stance (assuming the player stands with his feet fanned slightly), then adjust the pitch/roll based on the normal of the downward trace.