Uneven camera movement during roll

I have a camera inside a cockpit that Slerps to match the cockpit's orientation. This provides a nice sway effect when flying but produces a laggy/ uneven movement during a roll.

I have narrowed the culprit down to the up vector of the Slerp. The camera needs to match the cockpit's Transform.up vector but this causes a jagged motion only during a roll. This problem goes away if both the camera script and cockpit script use FixedUpdate() but since rigidbodies are not used, this creates other problems elsewhere.

I have also dug through a ton of other questions looking for something that might help me but to no avail. Any help would greatly appreciated.

The camera's C# script:

 // Update is called once per frame
     void LateUpdate () 
     {
 
         //smooth upVector to try to prevent jitter
         upVector = Vector3.SmoothDamp(upVector, target.up, ref smoothVelocity, 0.1f);
 
 
         //slerp to match cockpit rotation
         myTransform.localRotation = Quaternion.Slerp(myTransform.localRotation,
                                                      Quaternion.LookRotation(target.forward, upVector),
                                                      Time.deltaTime * reboundSpeed);
 
 
         
 
         //match cockpit position
         myTransform.position = target.position;
 
 
     }

How I'm getting my roll value in the cockpit's controller script Update() function:

 //smooth the roll input
     roll = Mathf.Lerp(roll, Input.GetAxis("Horizontal") * 2, Time.deltaTime * 5 );
     
     //ship rolls from roll input
     shipTransform.Rotate(0,0,-roll);